Some Republican senators who voted for Obamacare repeal legislation could regret it down the road.

Early Friday morning, the Senate voted down a last-ditch effort by Republicans to repeal and replace Obamacare, delivering a blow to Senate Leader Mitch McConnell and the rest of a party that promised for seven years to repeal the legislation. But the members who may pay the highest price are Republican senators in battleground states who supported the bill and are up for re-election next year.

Take Sen. Dean Heller of Nevada, one of 49 Republicans to vote in favor of the so-called “skinny repeal” proposal on Friday. Heller is the lone GOP senator up for re-election in a state Hillary Clinton won in 2016. He’s now on the record voting for an extremely unpopular bill that could have resulted in millions of Americans losing their insurance.

Democrats will try to ensure that he pays for that vote. Priorities USA, the powerhouse Democratic super PAC, has already released an online ad targeting Heller for his health care position.

“That’ll continue,” Patrick McHugh, the executive director of Priorities USA, said about the attack ad against Heller. “I think you’ll see advertising and communications educating voters [about who] voted for Trumpcare from now until Election Day. I don’t think it’s gonna stop.”

Rep. Jacky Rosen, a Democrat running for Heller’s seat next year, slammed the senator for the vote. “No politician from our state has ever been more dishonest about their intentions, more misleading about their position or more disingenuous to their constituents,” Rosen said in a statement. “This was the biggest broken political promise in modern Nevada history.”

In the weeks leading up to the healthcare vote, Heller—who waffled over the bill—was pressured by both wings of the Republican Party. Nevada Gov. Brian Sandoval, a Republican with high approval ratings, urged him not to support a bill that would gut Medicaid and decrease the number of insured. Meanwhile, pro-Trump Republicans were pressuring Heller to back an Obamacare replacement. America First Policies, a non-profit group that promotes the administration’s positions, launched an attack against Heller. (The group later pulled the ads.)

Heller, who barely won in 2012, may be the most vulnerable GOP candidate in a year when the Senate map looks very good for the party. But he’s not the only one.

Sen. Jeff Flake of Arizona cast votes for the motion to proceed and all three GOP plans. Flake is on shaky ground back home: according to a Morning Consult poll released in July, just 37% of registered Arizona voters approve of the senator.

Several Democratic challengers have emerged as possible candidates to run against Flake, including Rep. Kyrsten Sinema and Phoenix Mayor Greg Stanton, according to the New York Times. And Flake’s votes may be a liability in the race. According to a poll released on Thursday, just 6% of Arizona voters backed the Senate’s plan to repeal and replace Obamacare.

McHugh, the spokesman for Priorities USA, said the group would hold Heller and Flake accountable for their votes. “Now we have them on the record in support of a replacement plan,” he said, that polls show is “politically toxic.”

Spokesmen for Heller and Flake did not immediately respond to a request for comment.

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Write to Jack Brewster at jack.brewster@time.com.