"I'm disappointed with both the massive, bloated, secretive bill that just passed and with the president's intention to declare an emergency to build a wall," Paul announced.

Although he previously praised Trump's negotiating prowess in acquiring border security funds, he was dismayed by both the overall level of spending in the final legislation and the procedural approach adopted to ensure its speedy passage.

"I, too, want stronger border security, including a wall in some areas," he added. "But how we do things matters. Over 1,000 pages dropped in the middle of the night and extraconstitutional executive actions are wrong, no matter which party does them."

Paul was joined by a minority of Republicans in opposing the deal, which passed the Senate 83-16. Other notable Republican votes against were Sen. Tom Cotton (R-AR), Sen. Josh Hawley (D-MO),  Sen. Mike Braun (R-IN), Sen. Ted Cruz (R-TX), Sen. Mike Lee (R-UT), Sen. Marco Rubio (R-FL), Sen. Ben Sasse (R-NE), and Sen. Tim Scott (R-SC).