WASHINGTON -- Frustration with the botched, politically uncomfortable rollout of the president's health care law is beginning to mount to unsustainable levels among congressional Democrats.

On Wednesday morning, Sen. Jeff Merkley (D-Ore.) announced that he was co-sponsoring a bill to allow individuals who buy their own insurance to stay on their current health care plans indefinitely rather than be forced into better regulated plans through the newly created exchanges.

Coming from one of the Senate's most notably progressive voices, the Oregon Democrat's announcement was a particularly vivid demonstration of how nervous party members are over the state of the Affordable Care Act. The flawed website, combined with the steady stream of news of insurers forcing people to adopt more comprehensive and at times expensive plans in response to new regulations, had already persuaded five other Democrats to support the Keeping the Affordable Care Act Promise Act, introduced by Sen. Mary Landrieu (D-La.).

Meanwhile, in the House, patience among Democrats was wearing remarkably thin. Lawmakers in that chamber were, by and large, staying away from a Republican-pushed measure that would allow people to stay on their plans for another year. But top aides were warning of a swarm of potential defections should the Obama administration not introduce its own administrative fix for the issue of canceled health insurance plans by the end of the week.

At a caucus meeting on Wednesday, they relayed those frustrations directly to administration officials. Those officials, along with House Minority Leader Nancy Pelosi (D-Calif.) and House Minority Whip Steny Hoyer (D-Md.), urged members to oppose the GOP measure sponsored by Rep. Fred Upton (R-Mich.), arguing that it would gut a major component of Obamacare.

A Democratic aide said that the case being made against the Upton bill was multilayered. Not only would it allow current policyholders to continue their coverage, opponents argue, but it would allow new applicants to purchase that coverage as well -- all but encouraging healthy individuals to avoid the exchanges in favor of cheaper plans while leaving sick and older Americans in the newly created marketplace. The other major problem with the Upton bill that the aide noted was that it would extend this grandfather provision for just a year, meaning that people would be receiving cancellation notices in October of next year, a month before the 2014 elections. This, the aide noted, would be "problematic."

On Tuesday, White House press secretary Jay Carney said of the Upton plan, "We do not see that as fixing the problem. We see that as throwing the baby out with the bathwater." But his comments were bill-specific. Asked if the same rejection applied to the Landrieu legislation, an Obama administration official said that Carney was only addressing Upton's version.

The administration official didn't return a request for comment as to whether the president would support the Landrieu bill. Democrats have their concerns with it, too. As one health care advocate noted, it is written in a way that would basically require insurers to grandfather plans indefinitely, which would largely neuter the consumer protections that the ACA sought to apply to the individual insurance market. And while the bill requires insurers to remind those with grandfathered plans that they might have better options in the exchanges (including tax credits to help buy coverage), it's an unanswerable question as to whether that would be sufficient to get people to go to the exchanges over time. The possibility of adverse selection undermining the exchanges would remain.

There are political complications to the Landrieu bill as well. Even as it gained another Democratic co-sponsor on Wednesday, it was losing Republican support. A spokesman for Senate Minority Leader Mitch McConnell (R-Ky.), who supports a version of the keep-your-plan legislation from Sen. Ron Johnson (R-Wis.), told The Huffington Post that he didn't believe his boss would sign on to Landrieu's alternative

Grover Norquist's Americans for Tax Reform, meanwhile, came out fully against Landrieu's bill because it could be interpreted as a mandate that insurance companies keep offering certain plans indefinitely.

Then there is the question whether any of these bills could possibly work. After all, hundreds of thousands of cancellation notices have already gone out from insurers. A law that would essentially nullify those cancellation letters would require a huge administrative undertaking to execute. Insurers would have to send out updated letters, they'd have to ensure that the old plans complied with state regulations, and they'd have to re-enroll individuals who wanted to retain their policies.

"I'm sure the industry would like to do this. Don’t get me wrong. But everyone has to realize it took the insurance industry the better part of the year here to get ready for this," said Robert Laszewski, a health insurance industry consultant at Health Policy and Strategy Associates and a skeptic about the ACA. "It is practically impossible to do this. You can't put the genie back in the bottle. The insurance industry was ready for Obamacare but the Obama administration is not. When the Obama administration hit the go button, the dominoes were set in motion."

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  • 1912

    Former President Theodore Roosevelt champions national health insurance as he unsuccessfully tries to ride his progressive Bull Moose Party back to the White House. (Photo by Topical Press Agency/Getty Images)

  • 1935

    President Franklin D. Roosevelt favors creating national health insurance amid the Great Depression but decides to push for Social Security first. (Photo by Keystone/Getty Images)

  • 1942

    Roosevelt establishes wage and price controls during World War II. Businesses can't attract workers with higher pay so they compete through added benefits, including health insurance, which grows into a workplace perk. (Photo by Hulton Archive/Getty Images)

  • 1945

    President Harry Truman calls on Congress to create a national insurance program for those who pay voluntary fees. The American Medical Association denounces the idea as "socialized medicine" and it goes nowhere. (Photo by Keystone/Getty Images)

  • 1960

    John F. Kennedy makes health care a major campaign issue but as president can't get a plan for the elderly through Congress. (Photo by Keystone/Getty Images)

  • 1965

    President Lyndon B. Johnson's legendary arm-twisting and a Congress dominated by his fellow Democrats lead to creation of two landmark government health programs: Medicare for the elderly and Medicaid for the poor. (AFP/AFP/Getty Images)

  • 1974

    President Richard Nixon wants to require employers to cover their workers and create federal subsidies to help everyone else buy private insurance. The Watergate scandal intervenes. (Photo by Keystone/Getty Images)

  • 1976

    President Jimmy Carter pushes a mandatory national health plan, but economic recession helps push it aside. (Photo by Central Press/Getty Images)

  • 1986

    President Ronald Reagan signs COBRA, a requirement that employers let former workers stay on the company health plan for 18 months after leaving a job, with workers bearing the cost. (MIKE SARGENT/AFP/Getty Images)

  • 1988

    Congress expands Medicare by adding a prescription drug benefit and catastrophic care coverage. It doesn't last long. Barraged by protests from older Americans upset about paying a tax to finance the additional coverage, Congress repeals the law the next year. (TIM SLOAN/AFP/Getty Images)

  • 1993

    President Bill Clinton puts first lady Hillary Rodham Clinton in charge of developing what becomes a 1,300-page plan for universal coverage. It requires businesses to cover their workers and mandates that everyone have health insurance. The plan meets Republican opposition, divides Democrats and comes under a firestorm of lobbying from businesses and the health care industry. It dies in the Senate. (PAUL J. RICHARDS/AFP/Getty Images)

  • 1997

    Clinton signs bipartisan legislation creating a state-federal program to provide coverage for millions of children in families of modest means whose incomes are too high to qualify for Medicaid. (JAMAL A. WILSON/AFP/Getty Images)

  • 2003

    President George W. Bush persuades Congress to add prescription drug coverage to Medicare in a major expansion of the program for older people. (STEPHEN JAFFE/AFP/Getty Images)

  • 2008

    Hillary Rodham Clinton promotes a sweeping health care plan in her bid for the Democratic presidential nomination. She loses to Obama, who has a less comprehensive plan. (PAUL RICHARDS/AFP/Getty Images)

  • 2009

    President Barack Obama and the Democratic-controlled Congress spend an intense year ironing out legislation to require most companies to cover their workers; mandate that everyone have coverage or pay a fine; require insurance companies to accept all comers, regardless of any pre-existing conditions; and assist people who can't afford insurance. (Alex Wong/Getty Images)

  • 2010

    With no Republican support, Congress passes the measure, designed to extend health care coverage to more than 30 million uninsured people. Republican opponents scorned the law as "Obamacare." (Mark Wilson/Getty Images)

  • 2012

    On a campaign tour in the Midwest, Obama himself embraces the term "Obamacare" and says the law shows "I do care." (BRENDAN SMIALOWSKI/AFP/Getty Images)