Health care reformers’ million-dollar thank-you card to moderate Democrats.

Lobbying—in Washington, it’s often called “issue advocacy”—is a game of carrots and sticks: Support our issue and we’ll make life good for you. Oppose it and we’ll make it hell. Sometimes groups take a moment to just pause and say, “Thank you.” But what looks and sounds like gratitude is just another form of persuasion.

When Rep. Dina Titus, D-Nev., arrived at the airport in Las Vegas on Sunday, the morning after voting for the House health care reform bill, she was greeted by a dozen or so people waving giant “Thank You” signs (as well as a few less friendly opponents of reform). Starting Tuesday, Titus will also have her own personal “thank you” ad, produced by Health Care for America Now!, running in her district for a week. She may also get a “thank you” rally held in front of her office by MoveOn later this week.

In other words, liberal groups will be drawing as much attention to her controversial, potentially damaging vote as possible. Titus’ district is considered one of the most vulnerable in the state—both she and Obama won there in 2008 by only a few points. It’s a divided district. Is broadcasting her vote really the best way to thank someone for taking a tough stance on an issue equally likely to mobilize her opponents as motivate her supporters?

Health reform advocates recognize there’s some risk. “That is a consideration,” said Mike Ginsburg, whose group, Progressive Leadership Alliance of Nevada, organized the Titus airport rally. For example, a group of protesters caught wind of the airport event and showed up bearing anti-reform signs. But, says Ginsburg, pro-reform groups shouldn’t muzzle themselves just because there’s going to be some opposition: “They’re going to show up one way or the other.”

That seems to be the logic behind the latest campaign by MoveOn and HCAN: Positive reinforcement works. HCAN is running ads in 20 congressional districts across the country thanking Democrats for supporting the bill, and Americans United for Change will run spots in an additional 10 districts. (Watch the first batch here.) The total ad buy is about $1 million—a good chunk of the $8 million HCAN has spent on TV ads so far this year. MoveOn, meanwhile, is holding “thank you” rallies for at least 60 members.

And while broadcasting a member’s vote might hurt her among a small segment of voters, it’s not like her vote is going to be a secret. “Let’s be honest, Republicans are gonna raise hell in these districts anyways,” said an official at a progressive organization who preferred not to be named. “There’s no way they’re gonna let it go quietly.” Indeed, Republicans are already gearing up to smack down the couple dozen moderate Blue Dog Democrats who voted for the bill. Independent groups like Americans for Prosperity are asking members to thank their congressmen for opposing it. Reformers would rather broadcast their support, therefore, than keep quiet from fear that they’ll alienate constituents.

Members of Congress don’t seem to mind. “It helps us for sure,” said Jamie Radice, a spokeswoman for Carol Shea-Porter, a New Hampshire Democrat who voted for health care. Andrew Stoddard, a spokesman for Rep. Titus, agreed: “People know what’s going on with this [health care] more than in the past.” If a voter opposes a member of Congress because of these ads, they were probably going to oppose her anyway.

“Thank you” is a friendly sentiment, but it’s really saying three things: Thank you for voting for the House bill, even though it might hurt you politically. Heads up to your constituents that health care reform is going to help them, not hurt them. And don’t you dare consider backing down the second time around. “We’re definitely encouraging them to vote this way again,” says Jacki Schechner of HCAN.

In classic carrot/stick form, MoveOn is stimultaneously threatening to take down any Senate Democrats who oppose health care reform. They’re already running ads criticizing Democrats who voted against the bill. Meanwhile, members of MoveOn have pledged a total of $3.5 million to fund primary challenges against any dissident Dems. If a promise to thank you for supporting health care reform doesn’t work, maybe a threat to punish you for opposing it will.