Updated: 11:59 p.m.

Rep. Connie Mack IV will enter the Senate race in Florida, the Republican’s chief of staff confirmed to Roll Call late Wednesday.

“Connie is running and is confident he will beat liberal Senator Bill Nelson,” Jeff Cohen said in an email. “There will be a more formal announcement in the weeks ahead, but in the meantime he is making calls, assembling a team and preparing to run and win.”

The Miami Herald first reported Mack’s decision to run Wednesday, citing senior adviser David James. Mack has also informed National Republican Senatorial Committee Chairman John Cornyn (Texas) about his plans.

No frontrunner has emerged in the GOP primary to take on two-term Sen. Bill Nelson (D), and no candidate has fired up the Republican Party base.

Mack had endorsed state Senate President Mike Haridopolos against former state House Majority Leader Adam Hasner, former Sen. George LeMieux and retired Army officer Mike McCalister in the primary. But Haridopolos dropped out of the race less than a month later, citing conflicting responsibilities between his state Senate duties and his campaign.

Former Ruth’s Chris CEO Craig Miller entered the GOP primary after Mack’s endorsement, but he is not seen as a serious contender by establishment Republicans.

Mack, a four-term House Member, brings statewide name recognition to the race. Nelson succeeded Mack’s father and namesake, Connie Mack (R), in the Senate. The younger Mack, married to fellow Rep. Mary Bono Mack (R-Calif.), had $348,000 in cash on hand at the end of September, all of which can be transferred to a Senate campaign.