Rand Paul is dropping out of the 2016 race for president.

Paul said in a statement that he will turn his full attention to his Senate re-election campaign in Kentucky. The 52-year-old ophthalmologist is favored to win that race.

The first-term senator from Kentucky exits the race having never caught on with Republican voters, who have made billionaire businessman Donald Trump the front-runner in the race for the party's nomination.

Paul was determined to improve the GOP's popularity among younger voters and minorities. But his message failed to catch on and his appeal never broadened beyond the small group of libertarian-leaning Republicans that backed the previous White House bids of his father, Ron Paul.

Florida Sen. Marco Rubio says he will try to persuade some of Kentucky Sen. Rand Paul's supporters to redirect their support to him, despite the stark differences the two have on foreign policy.

After an event in Bow, N.H. Wednesday, Rubio said he and his now-former rival have "had some policy disagreements," especially on national security issues. But he called Paul a "real believer" in the issues that matter to him.

Both men were elected to the Senate during the rise of the tea party in 2010.

Copyright 2016 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.