President Donald Trump’s “big, beautiful bill” may already be on life support in the Republican-controlled Senate, and that’s only if it makes it out of the House, which has an even slimmer GOP majority.

CNN reporter Manu Raju tweeted Monday that the bill already faces opposition from two Republican senators—Ron Johnson (R-Wis.), who voiced concerns about the impact on the federal deficit, and Rand Paul (R-Ky.), who opposed raising the debt ceiling.

Raju noted that if two additional moderate Republicans, such as Sens. Susan Collins (R-Maine) and Lisa Murkowski (R-Alaska), join in opposition, it would effectively doom Trump’s chances of passing the legislation as currently drafted.

Typically, Senate legislation requires 60 votes to overcome a threatened filibuster. However, under the Senate’s budget reconciliation rules, measures strictly related to budget issues can pass with a simple 51-vote majority—meaning Republicans only need 50 votes plus a tie-breaking vote from Vice President JD Vance to secure passage.