As soon as the House approved the GOP health care bill on Thursday, Democrats were working on using it against Republicans in next year's midterm elections.

"They have this vote tattooed on them. This is a scar they carry," House Minority Leader Nancy Pelosi declared just after the American Health Care Act passed the House.

Just to rub it in, many Democrats on the House floor began singing "Na Na Hey Hey Kiss Him Goodbye" to their colleagues across the aisle after the vote, a moment of schadenfreude as they hope for the same fate many of their own suffered after the Affordable Care Act, also known as Obamacare, was passed in 2010.

Democrats need to flip 24 seats to win back the House in 2018, and the congressional vote to repeal and replace Obamacare may well have made that a much easier task. Some of the most vulnerable House Republicans voted in favor of the GOP health care plan on Thursday. No Democrats voted for it, while 20 Republicans opposed it, and it only eked by with 217 yay votes — one more than it needed to pass.

Even members who bit the bullet and voted yes, on what they admitted was an imperfect bill, sounded anything but certain about the vote they had just cast.

Florida Rep. Carlos Curbelo — who represents a Miami district Hillary Clinton won in 2016 by 16 points — made a "game-time decision" to vote for the legislation, his spokeswoman told the Miami Herald, and now will be looking to the Senate to smooth out some issues with the bill.

"Today's vote is just a step in the legislative process for this bill — not the end of it," Curbelo said in a taped statement. "We have worked hard to improve the legislation, but we have a long way to go."

The bill has yet to be scored by the nonpartisan Congressional Budget Office to determine how much the bill will cost or how many people could lose coverage. A CBO report in March on an earlier iteration of the bill predicted that 24 million fewer people would be covered.

Atop Democratic target lists for 2018 are the 23 Republicans who sit in districts that were won by Hillary Clinton last November. Of those members, 14 ended up voting for the bill, with just nine opposing it. One of those no votes, Florida Rep. Ileana Ros-Lehtinen, announced earlier this week she wasn't seeking re-election, so that's one open race Democrats are feeling hopeful about.

Many of the Republicans who voted against the bill cited concerns that the legislation didn't do enough to protect people with pre-existing conditions — echoing a major attack line that Democrats are already using and will surely stick with over the next 18 months.

Moderate New Jersey Republican Tom MacArthur worked with members of the conservative Freedom Caucus to come up with an amendment to the GOP's American Health Care Act that allows states to seek waivers from Obamacare requirements, including on coverage for people with pre-existing conditions.

Further changes put more money toward so-called "high-risk pools" to help defray costs for people with pre-existing conditions. But NPR's Alison Kodjak reported that "an analysis released Thursday by consulting firm Avalere Health concludes that that amount would be inadequate for providing full health coverage for the number of people who now buy insurance in the individual market and have medical problems."

"At this time, I cannot support the AHCA with the MacArthur amendment because I'm concerned that a small percentage of those with pre-existing conditions may still not be protected," Colorado Rep. Mike Coffman, who sits in a district Clinton won, said in a statement explaining his decision.

For Democrats, it's a pronounced turn of events since Obamacare passed in 2010. With Republicans riding high on the public opposition to the law, the Democrats' majority in the House was decimated that year, with 63 seats and control of the House lost.

But sentiment has changed on Obamacare, with Gallup Poll finding this month that 55 percent now approve of the ACA.

The AHCA faces a much tougher road in the Senate, and if it dies there, some of those vulnerable GOP members may have made what ends up being a futile vote.

But there's another side to consider, too. For Republicans who have made the refrain "repeal and replace Obamacare" their mantra for seven years now, not acting on their signature campaign promise could risk depleting enthusiasm among their core voters, who they also need to turn out in November 2018 to combat a Democratic base that is energized against President Trump.

And after the first attempt at repeal failed in an embarrassing fashion, House Republicans and Trump badly needed a win. That's why they took a victory lap in the White House Rose Garden on Thursday afternoon, even though the bill is far from becoming law.

"The American people expected us to deliver on the promises we've made and that's what House Republicans have just done," National Republican Congressional Committee communications director Matt Gorman wrote in a memo after the vote.

Republicans have pointed out that more insurance companies are pulling out of state-run exchanges, and the GOP bill will cut about $765 billion in taxes over the next decade, NPR's Scott Horsley reported, though mostly for wealthy Americans.

Some Democratic operatives were already gloating on social media that the Rose Garden event provided great footage for attack ads against House Republicans next year.

Ultimately, for the most vulnerable House Republicans, this may be a vote they won't be able to escape over the next year and a half — even if it never becomes law.

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