Sen. Marco Rubio, R-Florida, said Monday for the first time during his re-election campaign that he would serve a full six-year term if re-elected to the Senate, but did not shut the door on another presidential bid.
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In the first Florida Senate debate, moderated by ABC News' Chief White House Correspondent Jonathan Karl, Rubio defended his record from criticism that he missed a significant number of hearings and votes in his first time while running for president.
"I'm going to serve in the Senate for the next six years, God willing," he said. "Not only am I going to serve in the Senate over the next six years, we're going to get a lot done."
"So, this means you're not running for president?" Karl asked.
In his response, Rubio did not rule out a 2020 presidential run.
"I'm going to be a senator for the next six years on behalf of the state of Florida," he said. "You can't be a senator and president at the same time."
Before Monday night, Rubio had not committed to serving a full second term in Congress.
Between July of 2015 and September of 2016, Rubio missed 104 of 270 Senate roll call votes, nearly 40 percent of all votes.
Rep. Patrick Murphy, D-Florida, his Democratic opponent, repeatedly criticized Rubio during Monday's debate for his attendance record.
"We have a senator with one foot out the door, who will not even show up to work," Murphy said.
"I didn't like missing the votes, but like every sitting senator in the history of this republic that mounted a credible campaign for the presidency, I did," Rubio said in his defense.
While Murphy has slammed Rubio's record, he's also missed official congressional business for campaigning.
In May, he skipped a House Intelligence Committee meeting to campaign with Vice President Joe Biden in Orlando.
A new Senate poll from Quinnipiac University shows Rubio and Murphy are neck-and-neck heading into the final three weeks of the election.
The survey, taken before the Senate debate, has Rubio at 49 percent, and Murphy at 47, within the poll's margin of error.