With Sens. Rand Paul and Thom Tillis opposed to the package, GOP leaders can afford only one more defection. And multiple Republicans aren't yet sold on the measure.

A marathon voting session on President Donald Trump’s sweeping domestic policy bill is underway in the Senate and has stretched overnight into Tuesday after a weekend of negotiations and delays.

Republican leaders were pushing for a final vote to pass their marquee tax cut and domestic policy legislation, but had yet to resolve major issues after an all-night session of voting and negotiations.