A new analysis showing the legislation would be far more expensive than the House version could complicate its chances of final passage in that chamber, where fiscal hawks have said the cost must not grow.

The Senate has started formal debate on the Trump administration's budget reconciliation bill after lawmakers spent 16 hours reading the entire measure aloud on the Senate floor. This Senate's version of the budget measure would make deeper cuts to social service programs and lead to fewer people having insurance than previous versions,

One major sticking point for Republican fiscal hawks is the megabill’s proposed $5 trillion debt ceiling increase.