WASHINGTON -- President Barack Obama and Republican challenger Mitt Romney both have softened their positions on gun restrictions over the years. As they expressed shock and sorrow over the bloodshed at a Colorado movie theater, neither suggested that tougher gun control could make a difference, a notion that has faded from political debate.

Romney signed a ban on assault weapons as Massachusetts governor. But as the presumptive Republican nominee, he now bills himself as the candidate who will protect gun owners' rights.

Obama called for reinstating the federal ban on assault weapons during his 2008 presidential campaign. But since his election, he hasn't sought to get that done or pushed other gun control proposals, either.

Neither man is likely to raise gun control as a campaign issue – beyond Romney's insistence that an Obama presidency is bad for gun owners. Both say they'll protect the Second Amendment right to bear arms. A look at the evolution of the candidates' positions and where they stand on guns:

OBAMA

1997-2004: As an Illinois state senator, Obama supports banning all forms of semiautomatic weapons and tighter state restrictions generally on firearms, including a failed effort to limit handgun purchases to one per month.

2005: In the U.S. Senate, Obama votes against protecting firearms makers and dealers from lawsuits over misuse of their products by others. The bill is signed into law by President George W. Bush.

2008: During his first presidential campaign, Obama supports a return to the federal ban on assault weapons, which began during the Clinton administration and expired under Bush. He also endorses requiring background checks for buyers at gun shows. The National Rifle Association attacks him as an anti-gun zealot – a stand the group continues to take today.

April 2008: Obama is criticized for elitism after sounding dismissive of gun owners in a talk to campaign donors. He said voters in struggling small towns in Middle America "cling to guns or religion or antipathy to people who aren't like them" to explain their frustrations.

September 2008: Obama seeks to reassure gun owners: "I believe in people's lawful right to bear arms. ... There are some common-sense gun safety laws that I believe in. But I am not going to take your guns away." Nonetheless, gun sales go up when Obama wins, apparently because of fear that new restrictions are imminent under his administration.

2009: As president, Obama signs a law allowing people to carry concealed weapons in the Grand Canyon, Yellowstone and other national parks and wildlife refuges and another that lets people carry guns in their checked bags on Amtrak trains.

2010: The Brady Center to Prevent Gun Violence gives Obama a grade of "F" for failing to push even the gun restrictions he supported while campaigning.

2011: Obama says the shooting that severely wounded then-Rep. Gabriel Giffords, D-Ariz., and killed six people should lead to "a new discussion of how we can keep America safe for all our people." He calls for "sound and effective steps" to keep guns out of the hands of criminals, including strengthening background checks on gun buyers. But he's short on specifics, and the Obama administration hasn't proposed any new gun initiatives since then.

March 2012: Obama calls the fatal shooting of black teenager Trayvon Martin by a neighborhood watch volunteer in Florida "a tragedy," saying Americans should do some soul-searching and "examine the laws" to figure out why it happened. He hasn't called for any legal changes in response to the case, which mostly brought attention to some states' "stand your ground" laws making it easier for a shooter to claim self-defense. Indeed, most gun regulations are imposed by states. The primary federal law is the Brady law requiring background checks on firearms purchasers.

July 20: Obama says he's heartbroken by the Aurora, Colo., movie theater massacre and calls for Americans to unite in prayer for the victims: "If there's anything to take away from this tragedy it's the reminder that life is very fragile, our time here is limited and it is precious."

Asked whether the mass shooting should prompt a new review of gun laws, White House spokesman Jay Carney declines to comment beyond reiterating Obama's existing stance in support of "common-sense measures that protect Second Amendment rights of Americans, while ensuring that those who should not have guns under existing law do not get them."

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ROMNEY

1994: In his unsuccessful challenge to liberal Democratic Sen. Edward M. Kennedy, Romney sounds moderate on guns, supporting an assault weapons ban and insisting, "I don't line up with the NRA."

2002: Running for governor of Massachusetts, Romney says he supports and will protect the state's "tough gun laws." The NRA gives his Democratic opponent a higher rating on gun-rights issues and makes no endorsement in the race.

2003: As governor, Romney upsets gun owners by signing a law that quadruples the state's gun-licensing fee – from $25 to $100 – as part of a widespread effort to eliminate the budget deficit.

2004: Romney signs a Massachusetts ban on assault weapons. He mollifies many gun rights advocates by coupling it with looser rules on gun licenses and an extension of the duration of licenses, reducing the effect of the earlier fee increase.

2005: Declares May 7 as "Right to Bear Arms Day" in Massachusetts.

2006: As he prepares for his first presidential run, Romney becomes a lifetime NRA member.

2007: While campaigning, Romney declares he sometimes hunts "small varmints" – a comment ridiculed by some as an awkward attempt to pander to pro-gun voters.

2008: In a Republican primary debate, Romney says he would have signed the federal assault weapons ban if it came to his desk as president, but he opposes any new gun legislation.

2011: Making his second presidential bid, Romney's campaigns on a promise to protect and promote the Second Amendment.

2012: Romney tells gun owners that Obama wants to erode their rights. "We need a president who will enforce current laws, not create new ones that only serve to burden lawful gun owners," Romney told the National Rifle Association's annual convention. "President Obama has not. I will."

July 20: Like Obama, Romney avoids talking politics on the day of the Aurora shooting. He says Americans are coming together in their sorrow: "There is something we can do. We can offer comfort to someone near us who is suffering or heavy laden, and we can mourn with those who mourn in Colorado."

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  • 1981: The Attempted Assassination Of President Ronald Reagan

    on March 30, 1981, President Reagan and three others were shot and wounded in an assassination attempt by John Hinckley, Jr. outside the Washington Hilton Hotel in Washington, D.C. Reagan's press secretary, Jim Brady, was shot in the head.

  • 1993: The Brady Handgun Violence Act

    The Brady Handgun Violence Act of 1993, signed into law by President Bill Clinton, mandated that federally licensed dealers complete comprehensive background checks on individuals before selling them a gun. The legislation was named for James Brady, who was shot during an attempted assassination of President Ronald Reagan in 1981.

  • 1994: The Violent Crime Control and Law Enforcement Act

    The Violent Crime Control and Law Enforcement Act, signed into law by President Bill Clinton in 1994, instituted a ban on 19 kinds of assault weapons, including Uzis and AK-47s. The crime bill also banned the possession of magazines holding more than ten rounds of ammunition. (An exemption was made for weapons and magazines manufactured prior to the ban.)

  • 2004: Law Banning Magazines Holding More Than Ten Rounds Of Ammunition Expires

    In 2004, ten years after it first became law, Congress allowed a provision banning possession of magazines holding more than ten rounds of ammunition to expire through a sunset provision. Brady Campaign President Paul Helmke told HuffPost that the expiration of this provision meant that Rep. Gabby Giffords's alleged shooter was able to fire off 20-plus shots without reloading (under the former law he would have had only ten).

  • 2007: The U.S. Court of Appeals For The District Of Columbia Rules In Favor Of Dick Heller

    In 2007 The U.S. Court of Appeals for the District of Columbia ruled to allow Dick Heller, a licensed District police officer, to keep a handgun in his home in Washington, D.C. Following that ruling, the defendants petitioned the U.S. Supreme Court to hear the case.

  • 2008: The NICS Improvement Amendments Act

    Following the deadly shooting at Virginia Tech University, Congress passed legislation to require states provide data on mentally unsound individuals to the National Instant Criminal Background Check System, with the aim of halting gun purchases by the mentally ill, and others prohibited from possessing firearms. The bill was signed into law by President George W. Bush in January of 2008.

  • 2008: Supreme Court Strikes Down D.C. Handgun Ban As Unconstitutional

    In June of 2008, the United States Supreme Court upheld the verdict of a lower court ruling the D.C. handgun ban unconstitutional in the landmark case <em>District of Columbia v. Heller</em>.

  • Gabrielle Giffords And Trayvon Martin Shootings

    Gun control advocates had high hopes that reform efforts would have increased momentum in the wake of two tragic events that rocked the nation. In January of 2011, Jared Loughner opened fire at an event held by Rep. Gabrielle Giffords (D-Ariz.), killing six and injuring 13, including the congresswoman. Resulting attempts to push gun control legislation <a href="http://www.huffingtonpost.com/2012/04/09/trayvon-martin-shooting-gun-debate_n_1413115.html" target="_hplink">proved fruitless</a>, with neither proposal even succeeding in gaining a single GOP co-sponsor. More than a year after that shooting, Florida teenager Trayvon Martin was <a href="http://www.huffingtonpost.com/news/trayvon-martin" target="_hplink">gunned down</a> by George Zimmerman in an event that some believed would bring increased scrutiny on the nation's Stand Your Ground laws. While there has been increasing discussion over the nature of those statutes, lawmakers were <a href="http://www.huffingtonpost.com/2012/04/09/trayvon-martin-shooting-gun-debate_n_1413115.html" target="_hplink">quick to concede</a> that they had little faith the event would effectively spur gun control legislation, thanks largely to the National Rifle Association's vast lobbying power. Read more <a href="http://www.huffingtonpost.com/2012/04/09/trayvon-martin-shooting-gun-debate_n_1413115.html" target="_hplink">here</a>:

  • Colorado Movie Theater Shooting

    In July of 2012, a heavily armed gunman <a href="http://www.huffingtonpost.com/2012/07/20/aurora-shooting-movie-theater-batman_n_1688547.html" target="_hplink">opened fire on theatergoers</a> attending a midnight premiere of the final film of the latest Batman trilogy, killing 12 and wounding scores more. The suspect, James Eagan Holmes, allegedly carried out the act with a number of handguns, as well as an AR-15 assault rifle with a 100-round drum magazine. Some lawmakers used the incident, which took place in a state with some of the laxest gun control laws, to bring forth legislation designed to place increased regulations on access to such weapons, but many observers, citing previous experience, were <a href="http://www.huffingtonpost.com/2012/07/20/batman-shooting_n_1690547.html" target="_hplink">hesitant to say</a> that they would be able to overcome the power of the National Rifle Association and Washington gun lobby.