Just one month after tweeting that he'd "only said like 10000 times" that he'd be a "private citizen" come January, Sen. Marco Rubio (R-Fla.) appears to have changed his mind. In an interview with the Miami Herald, Rubio confirmed weeks of rumors that he'd been re-considering his decision to leave the Senate. "The point that really drove me to change my mind is that as we enter this kind of new chapter in our history [with the presidential election] ... there's another role the Senate plays that I think can be really important," Rubio said, "and that's the power given to it in the Constitution to act as a check and balance on the excess of the president."

Rubio had reportedly begun telling some Republicans about his change of plans. He reportedly reached out to Sen. Ted Cruz (R-Texas), another one-time 2016 presidential candidate, to ask for his endorsement, though aides say Cruz declined the request because he didn't want to "be accused of nudging out U.S. Representative Ron DeSantis, the tea-party favorite in the race for Rubio's seat," The Washingtonian reports. DeSantis suggested last week that he would consider dropping out if Rubio decided to run.

Rubio's entry in the race comes just days ahead of the Friday deadline for candidate filings, and at the behest of his Republican colleagues. A close friend of Rubio's, Florida Lt. Gov. Carlos Lopez-Cantera, has already told his supporters he'd back off if Rubio decides to run, and, last week, another Republican running for Rubio's seat, Rep. David Jolly, withdrew from the race.

Rubio is expected to make a formal announcement Wednesday afternoon. His candidacy greatly boosts the GOP's chances of retaining his Florida seat — one that could tip the Senate majority to either side of the aisle. Becca Stanek