The vote was on the American response to ISIS, but many senators had Iowa and 2016 on the mind.
More than two-thirds of the Senate voted Thursday to arm and train moderate Syrian rebels, but nearly all of the senators discussed as possible 2016 presidential candidates opposed President Barack Obama’s plan to combat ISIS, the militant group cutting a swath of terror in Syria and Iraq.
Twenty-two senators -- twelve Democrats, nine Republicans and one Independent -- voted against the Title X measure included in the continuing resolution to fund the government until mid-December.
“There is no guarantee of success,” Rubio said of training and arming Syrian fighters. “But there is a guarantee of failure if we do not even try, and try we must.”
Rubio’s affirmative vote hawkishly distanced the Florida Republican from Sens. Ted Cruz of Texas and Rand Paul of Kentucky, who both opposed the measure.
Cruz said that the moderate rebels in the Free Syrian Army would use American weapons and training against the Assad regime over ISIS.
“Resolving the Syrian civil war is not our mission, nor the job of the military,” Cruz said on the floor Thursday.
Paul, who has worked to distance himself from the “isolationist” label, said weapons provided to moderate rebels would end up with ISIS, but insisted he was not opposed to intervention.
“There are valid reasons for being involved, and I think we are doing the right thing but just in the wrong way,” Paul said of voting on Title X as part of the continuing resolution.
In the liberal opposition, Democratic Sen. Elizabeth Warren of Massachusetts and Independent Sen. Bernie Sanders of Vermont, who are considered potential challengers to former Secretary of State Hillary Clinton in 2016, both cast no votes against the president’s plan.
Sanders, a self-described democratic socialist who strongly opposed the Iraq war, said arming rebels could “open the door to the United States once again being involved in a quagmire.”
Warren did not speak on the Senate floor before voting Thursday. Sen. Kirsten Gillibrand, D-N.Y., who also voted against authorization, is thought to be mulling a future presidential bid like her predecessor Clinton.
These decisions could help distinguish Warren and Sanders from Clinton should they face off in 2016. While she did not weigh in on the Title X authorization specifically, Clinton urged President Obama to arm the Syrian rebels during her time as secretary of state.
Of the red-state Democrats facing tough re-election races in November, only Sen. Mark Begich voted against authorization.
Though he supports U.S. airstrikes, the Alaska Democrat said that Arab nations “need to step up to the plate” against ISIS. His Republican opponent, former state attorney general Dan Sullivan, supports arming the Syrian rebels.
Senators worried about the impact of their votes on potential presidential bids have some more fretting to do: they will have to vote on arming and training rebels once again when Title X expires in mid-December.
ABC News' Arlette Saenz and Jeff Zeleny contributed to this report.