The Senate is working against a midnight Friday deadline to pass a $1.3. trillion spending bill to keep the government from running out of money – but as he's done before – Kentucky Republican Rand Paul is threatening delays that could cause another shutdown.
Paul has said he wanted to read each of the bill's 2,200-plus pages before voting on it, and as of Thursday evening was tweeting excerpts that he found especially objectionable.
After House and Senate leaders reached a deal, the House approved the bill midday Thursday.
Thursday afternoon, Senate Majority Leader Mitch McConnell moved to end debate on the bill, triggering a 30-hour window senators can use to discuss it.
The debate time could be shortened if Paul and other senators unanimously agree to do so but it was unclear how far Paul would go to press his point.
If the whole 30-hour time is used, the earliest the Senate could vote to advance the so-called "omnibus" bill would be 1 a.m. Saturday morning.
The Senate would then have to wait even longer before taking any final vote to pass it.
The measure would fund the government through September 30, with Republicans hailing its large increase in military spending, $1.6 billion for border security and $600 million for election security resources.
White House budget director Mick Mulvaney says President Donald Trump will sign the bill despite not getting more of what he wanted - including more money for a border wall.
"In order to get the defense spending primarily, (and) all the rest of our priorities funded, we had to give away a lot of stuff that we didn't want to give away," Mulvaney said.