Just before the vote, Bridenstine's leading Democratic critic in the Senate wasn't backing away from his stern criticism of the three-term Republican Congressman from Oklahoma.
"The NASA Administrator should be a consummate space professional," said Sen. Bill Nelson (D-FL) in a speech on the Senate floor.
"That's what this Senator wants - a space professional - not a politician," Nelson added.
"Senators on both sides of the aisles have expressed doubts - both publicly and privately to me - about his qualifications for the job," said Nelson, who was the only Senator to address the matter before the vote on cloture, a procedure to end debate in the Senate.
Since Bridenstine was nominated for NASA Administrator in September, Rubio had sided with Nelson and other Democrats, raising questions about Bridenstine's ability to run a federal agency in a nonpartisan manner.
But that suddenly changed this week - and GOP leaders quickly moved to take the Bridenstine vote, moving the President a step closer to having his choice in the job as NASA chief.
The procedural vote on Bridenstine's nomination almost went awry, as Sen. Jeff Flake (R-AZ) voted "No," leaving the vote tied at 49-49.
Ordinarily, the Vice President would be brought in to break the tie, but Vice President Mike Pence was in Florida with President Trump, hosting the Japanese Prime Minister.
After a wait of over a half hour, Flake returned to the floor and voted "Yes," allowing the Senate to force an end to debate.