WASHINGTON -- "[T]hey're coming for your guns," blared the subject line of an email sent out by the campaign of Sen. Mitch McConnell (R-Ky.) in January as Congress began discussion on small-bore gun control legislation.

"You and I are literally surrounded," McConnell campaign manager Jesse Benton wrote in the email. "The gun-grabbers in the Senate are about to launch an all-out assault on the Second Amendment. On your rights. On your freedom."

The frantic email urged recipients to show their support for McConnell as he led "the Senate Republicans against this unconstitutional agenda" by signing a petition, which also contained a solicitation to donate to his reelection effort next year.

McConnell's email is a perfect example of how politicians, political parties and outside groups use overheated, fear-inducing rhetoric and hyperbole to scare up contributions in the never-ending quest for campaign money.

At the Fundraise to Win conference hosted by Campaigns & Elections magazine on Nov. 21, two top digital fundraising professionals -- New Blue Interactive's Taryn Rosenkranz and the Prosper Group's Kurt Luidhart -- explained exactly how campaigns get you to open their emails and then your wallet.

The key to successful digital fundraising, according to Luidhart, is to make online donors "feel passionate, angry, fear, outrage."

Scaring conservatives that Obama is about to take away their guns, as McConnell did, is quite literally what Luidhart, who develops digital fundraising strategies for conservative campaigns, labeled as a best practice to increase a GOP candidate's list of supporters and persuade them to dish out more donations.

"On the Republican side, I just pick the most partisan issues I can," Luidhart said. "I run these little petitions, ya know, stop Obama's gun grab, right? And you get all these gun owners that sign a little petition, and then I can educate them about my candidate and about how the other person is going to take their guns away."

Or you could go even further, as the South Carolina Republican Party did when it called the Internal Revenue Service "Obama's Gestapo" in a fundraising email.

These kind of urgent, partisan pitches were also on full display during the 16-day government shutdown in October. Both Democrats and Republicans blasted their supporters with appeals for money. The Democratic Congressional Campaign Committee romped its way to record fundraising months in September and October by attacking GOP "extortion tactics" and House Speaker John Boehner's "complete cave to Tea Party Republicans."

In the run-up to the shutdown, many email solicitations specifically asked supporters to make a small donation to help the campaign group post a strong fundraising number before its next campaign finance filing.

Every campaign wants to post strong fundraising numbers in its monthly or quarterly filings, and such an appeal tells people that their contributions will matter. Rosenkranz, who works with Democratic campaigns and groups, said this helps convert supporters into donors by making them feel personally invested.

"Everybody's talking about a deadline," Rosenkranz said. "Why that works is because it's a transaction. I'm giving money to help you give a strong showing at your Federal Election Commission deadline, because you're going to have to report out how much money you have in the bank and I'm going to help you to have a strong number. That's a transaction."

Transactions can also be formed through requests to help the campaign respond to attacks from outside groups or by calls to join an embattled candidate -- "We are a top target."

This strategy helps explain the constant appeals from President Barack Obama's 2012 reelection campaign, which claimed it might be outspent by the GOP -- in fact, it raised $690 million online -- and the constant refrain from multiple Democratic campaigns about the billionaire Koch brothers and outside conservative groups spending money in their races.

One of the Obama campaign's most successful fundraising emails started with the subject line, "I will be outspent."

The subject line might be the single most important element in a fundraising email. The campaign can't get you to open your wallet if you don't even open the email. One way campaigns fail here is by telling supporters they will be asked for money in the subject line, Rosenkranz said.

"Don't give away the punchline," she said, adding, "If they're looking for an excuse not to give, they're going to walk away from it if they know what it is."

The two fundraising professionals gave examples of effective subject lines that were intimate, vague, urgent and direct, but not necessarily all at the same time.

A recent email from Georgia Democratic Senate candidate Michelle Nunn led with the subject line, "They're not waiting." In another, Sen. Elizabeth Warren (D-Mass.) wrote, "That's what girls do."

Eye-catching subject lines do not necessarily need to go as far as the 2012 Obama email that enticed supporters with a simple "Hey." Although that email did turn out to be one of the most successful of the whole campaign.

Don't expect the barrage of fundraising emails to lighten up any time soon, especially if campaigns listen to Rosenkranz and Luidhart. Both said there is really no limit to the amount of email a campaign should be sending.

"I think you should ask them all the time," Luidhart said. "If your unsubscribe rate goes up, then you slow down a little bit, but really your email list -- just abuse it. You've got no use for it the day after the election."

However, candidates need to understand, according to both Rosenkranz and Luidhart, that digital fundraising is not going to replace candidates making personal phone calls and attending fundraisers this year or next.

"When I first meet with a candidate, the worst thing I can hear is, 'I'm really counting on you to raise all of my money,'" Luidhart said. "Don't try to be that person who thinks they don't have to call their friends and family and ask them for $2,000."

Rosenkranz added, "Yes, you still do have to do call time."

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