The future of the Senate Republican leadership's healthcare bill, released on Thursday, is already in doubt as at least five Republican senators have come out in opposition of the legislation in its current form.

Even if Majority Leader Mitch McConnell successfully wrangles his members and gets the bill through, though, he would run into another wall: House conservatives.

Despite substantial differences between the House's American Healthcare Act and the Senate's Better Care Reconciliation Act, The Hill's Scott Wong reported Thursday that a member of the House GOP conference close to the leadership said the Republican brass wanted to take up and pass whatever came out of the Senate.

That would suggest a breeze for Republicans' healthcare legislation to President Donald Trump's desk.

But some of the changes made in the Senate version of the bill are unlikely to fly with conservative members of the House, especially the House Freedom Caucus. The Freedom Caucus forced House Speaker Paul Ryan to pull the first version of the AHCA from the floor just minutes before a scheduled vote. They eventually won a number of concessions to the final version of the bill that passed.

Rep. Mark Meadows, head of the Freedom Caucus, poured cold water all over the idea of a quick passage on Friday. The North Carolina representative told reporters the Senate bill "does not have enough conservative support" to get by the House without changes.

Separately, a source close to the Freedom Caucus told Business Insider that while the group does not yet have an official position, since the members won't meet until Monday, it does have a preference.

"The Freedom Caucus strongly supports going to conference with the Senate on healthcare legislation," the source said.

That could mean weeks to come of negotiations to craft a bill that would not only satisfy the hardline conservatives in the Freedom Caucus, but also moderate Senate Republicans who are already wavering on a Senate bill that is less conservative than the AHCA.

For Republican leaders, that won't be an easy task.

Said Greg Valliere, the chief strategist at Horizon Investments: "Odds of enactment are still below below 50%, but the horse trading has just begun as this drama intensifies."