At this point, a vote is still possible on an amendment from Sen. Rand PaulRand PaulOvernight Defense: Military won't lift transgender ban until Trump sends directions | House passes national security spending | Russian sanctions bill heads to Trump Overnight Cybersecurity: Senate sends Russia sanctions bill to Trump | Senators unveil email privacy bill | Russia tried to spy on Macron with Facebook Senate sends Russia sanctions bill to Trump's desk MORE (R-Ky.) to extend the debt ceiling in line with the Obama administration's budget proposal (which Paul and other Republicans hope will fail). A vote may also happen on one from Sen. Jim DeMint (R-S.C.) that would repeal last year's Dodd-Frank law.

Both of these amendments had "pending" status on Thursday.

Others introduced mid-week (mostly from Republicans) have a less certain fate. Among other things, they would require the completion of the border control fence along the southern U.S. border, repeal some of the Federal Reserve's newfound authority under Dodd-Frank to supervise banks, set up a new congressional review procedure for questionable regulations, and even one to exempt "lesser prairie chicken" from the endangered species list.

The strong feelings Republicans have about their right to bring up amendments became evident at one point on Thursday when Sen. John McCainJohn McCainTrump blasts lawmakers for voting down 'skinny' ObamaCare repeal Senate defeats ObamaCare repeal measure McCain kills GOP's 'skinny' ObamaCare repeal plan MORE (R-Ariz.) thought one of his amendments was about to be blocked. His amendment would prohibit federal funds from being used to fund the construction of ethanol storage facilities or ethanol blending pumps.

"I understand the strength of the ethanol lobby, but there was an agreement that amendments could be called up," McCain said. "If that is not the case, I would obviously have to start with other parliamentary measures.”

McCain was allowed to offer his amendment.

Republicans, led by DeMint earlier in the week, assured that right to with a threaten to block the bill from coming to the floor if a deal struck by Senate leadership in January affording unlimited amendments to most legislation was not adhered to by Democratic leadership.

DeMint dropped his threat on Tuesday once he received assurances from the majority that the open amendment process would be followed.

The Senate adjourned at around 7:40 p.m. on Thursday and is set to return on Monday at 2 p.m.