WASHINGTON ― Before she voted for the Senate version of the Republican tax bill, Sen. Susan Collins saw that Congress would soon be passing separate spending deals, and she had demands.

The Maine Republican laid out a series of conditions for her to support the final “conference committee” version of the tax proposal. Most notably, she wants Congress to pass two separate health care bills first.

“I am pushing to make sure they are passed and signed into law prior to the conference report coming back on the tax bill so that I would know for certain we’re going to be able to mitigate the impact of the repeal of the individual mandate,” Collins told reporters before the vote last week.

The Senate tax bill would repeal the Obamacare requirement that everybody purchase health insurance or pay a fine. Collins was one of three Republicans to vote down attempts to repeal the Affordable Care Act earlier this year. She said that while she’d prefer that the tax legislation not repeal the individual mandate, with those two other pieces of legislation, the effects of that repeal wouldn’t be so bad.

It’s unclear how the separate health bills would become law before a final tax vote. Though Collins secured support from both President Donald Trump and Senate Majority Leader Mitch McConnell (R-Ky.), neither man controls the House of Representatives.

House Speaker Paul Ryan (R-Wis.) has suggested he doesn’t support the Collins demands, saying he wasn’t a party to her deal with McConnell. And Rep. Mark Walker (R-N.C.), leader of a group of lawmakers called the Republican Study Committee, said the conservative bloc had been promised by GOP leaders that the health bills would not be part of a must-pass spending package this month.

Collins wants Congress to pass the so-called Alexander-Murray deal — an agreement worked out between Sens. Lamar Alexander (R-Tenn.) and Patty Murray (D-Wash.) that would provide for “Cost Sharing Reductions” for Obamacare insurers — and another bill providing $2.25 billion annually for states to offset the high insurance costs of some individuals.

Without those measures signed into law, McConnell could just invite Collins to become the one remaining “no” vote Senate Republicans can afford, since their tax bill passed with 51 votes last Saturday.

Collins did influence the actual tax bill. For instance, she insisted that the Senate bill not fully repeal the state and local tax deduction, though the provisions Collins got mirrored House changes and were probably necessary for the bill to ultimately pass Congress anyway.

Other senators may also have misplayed the tax bill. Sen. Marco Rubio (R-Fla.) recently complained about the president’s newfound openness toward raising the corporate tax rate slightly from the 20 percent rate that GOP leaders insisted was sacred. Rubio had unsuccessfully pushed for increasing the rate to pay for a better child tax credit. And Sen. Jeff Flake (R-Ariz.) said he supported the tax bill partly on condition he’d be included in negotiations to protect undocumented immigrants who arrived in the U.S. as children, another policy conservatives don’t want in a spending deal.

It would be difficult for Republican leaders to appease Collins without betraying House conservatives.

On Thursday, they went along with a stopgap spending bill under the conditions that there would be no Alexander-Murray provisions in any of the other upcoming measures to fund the government. Ryan and House Republicans could very well pass another short-term appropriations bill in two weeks, have the Senate change the bill — because, after all, McConnell needs Democratic votes to pass that bill in his chamber — and then force Ryan and House Republicans to pass the Senate version or shut down government.

But no matter the ultimate conclusion, Collins is already being asked to accept more things on faith than she was supposed to. Earlier in the week, the House Freedom Caucus nearly derailed a vote to begin merging the separate versions of the tax legislation until leaders agreed to “decouple” the tax bill from the other spending bills, with Freedom Caucus Chairman Mark Meadows (R-N.C.) telling reporters that the final tax bill would now likely come next week, days before Senators vote again on a spending bill.

If that’s the case, Collins will once again be asked to vote for legislation she believes is harmful to Americans with the promise that Congress will mitigate their actions in the future.

If Collins objects, any one other Republican senator — with Bob Corker (R-Tenn.) continuing to oppose the bill — could sink the tax legislation. And other senators may hold up the process until Collins receivers firmer commitments. Sen. John McCain (R-Ariz.), for example, could have a problem with McConnell going back on his word.

But it should be clear at this point, to Collins and to House conservatives, that someone is going to get hoodwinked. At least one GOP leader is going to have to go back on his word. And it should be clear at this point that these commitments Republicans are making are a lot looser than members of Congress think.