Many Republicans assume their party will take another stab at repealing and replacing the Affordable Care Act if the midterm elections go their way, even though GOP candidates aren't making a big deal about it on the campaign trail.

What they're saying: "Repeal is like fight club," one GOP operative told me. "First rule is not to talk about it."

There's a decent chance Republicans won't be in a position to try again, in part because their last effort was so unpopular. Health care is front and center in Democrats' bid for the House majority, and recent polling shows that Democrats have an edge on the issue.

That's also part of the reason Republican candidates aren't campaigning on ACA repeal as aggressively as they have in the past.

But if Republicans hang onto the House and expand their majority in the Senate, lawmakers and aides generally assume another repeal vote would happen.

"I suppose that it’s all in the numbers, and if you had a significant enough shift in the Senate and you came up with a replacement that really did generate a level of support, yep," said Sen. Lisa Murkowski, who opposed last year's repeal bill.

That bill failed by just one vote in the Senate, and GOP candidates are emphasizing the ACA as they try to expand their one-seat majority.

Republicans challenging Democratic incumbents in places like Wisconsin and Montana have recently reiterated their opposition to the law. Two of those candidates — Patrick Morrisey in West Virginia and Josh Hawley in Missouri — are state attorneys general who have signed on to a new lawsuit arguing the ACA is unconstitutional.

There are two big obstacles: Losing too many House seats to pass a repeal bill there, and finding a replacement plan that could get more votes than the last effort.