Rep. Patrick Murphy (D-FL) speaks during a news conference with a bipartisan group of House members outside the U.S. Capitol May 20, 2014.
Washington CNN  — 

Florida Rep. Patrick Murphy made his long-expected Florida Senate bid official on Monday morning, giving Democrats their preferred candidate in the race.

“I’ve spent the last several months considering the best way I can continue to serve the people of Florida, and today, after much thought and discussion with people from across this state, I’m proud to announce that I will be a candidate for the United States Senate in 2016,” he said in a statement.

Murphy was openly contemplating a run and, in the clearest hint he was moving towards a bid, was spotted leaving a Democratic Senatorial Campaign Committee event last week, according to the Washington Post.

Republican Sen. Marco Rubio is expected to launch a presidential bid in the coming months, but he hasn’t yet made those plans official, and Murphy framed his bid as a challenge to the incumbent — but hinted at Rubio’s ambition — in his statement.

“For years, Senator Rubio has put the needs of Floridians behind his presidential ambitions. We need a leader in the Senate whose eyes are firmly fixed on the people of Florida by working together to get things done,” he said.

READ: Dems face primary battles of their own

National Democrats see Murphy as their strongest candidate for the race, as they believe his moderate profile fits the expansive and politically diverse state, and his fundraising abilities will help him compete in a race that many expect to cost $100 million.

But he may still face a primary challenge. Though Democratic National Committee Chairwoman Debbie Wasserman Schultz recently opted out of the race, Democratic Rep. Alan Grayson is still considering a bid.

Republicans have a wide array of potential contenders if Rubio does launch a presidential bid, including Florida Chief Financial Officer Jeff Atwater and a handful of the state’s members of Congress.