Republican U.S. Senator Rand Paul of Kentucky, a libertarian who often opposed American military intervention in overseas conflicts, dropped his bid Wednesday for the 2016 Republican presidential nomination, as did another low-polling candidate, former Pennsylvania Senator Rick Santorum.
Paul, a practicing ophthalmologist, won little support in the crowded Republican campaign, which currently is dominated by billionaire real estate mogul Donald Trump and two conservative senators, Ted Cruz of Texas and Marco Rubio of Florida. Paul finished fifth in this week's voting in the farm state of Iowa, collecting just 4.5 percent of the vote in statewide party caucuses.
Santorum, a vocal conservative, polled even lower, finishing 11th in the 12-way race with one percent of the vote. He had won the 2012 Iowa caucuses.
The departure of Paul and Santorum leaves 9 candidates in the Republican field. Mike Huckabee, the 2008 Iowa caucuses winner, dropped out Monday night after a ninth-place finish.
The next voting is set for Tuesday, a party primary in the northeastern state of New Hampshire.
Paul now faces a tough re-election fight this year in the mid-South state of Kentucky to keep his Senate seat for another six-year term.
"The fight is far from over," he said as he ended his presidential campaign. "I will continue to carry the torch for liberty in the United States Senate and I look forward to earning the privilege to represent the people of Kentucky for another term."
In one defiant legislative episode in 2013, Paul commanded the Senate floor for almost 13 hours in opposition to President Barack Obama's use of drones to attack suspected terrorists.
While that marathon speech won him support from many opposed to U.S. military operations, it did not translate into support in the Republican presidential campaign, where his opponents regularly have called for heightened military action against Islamic State terrorists beyond the aerial bombardment Obama is carrying out.