Republican presidential candidate Marco RubioMarco RubioOvernight Finance: Lawmakers float criminal charges for Wells Fargo chief | Scrutiny on Trump's Cuba dealings | Ryan warns of recession if no tax reform The Trail 2016: Just a little kick Opposition to Obama's radical disarmament agenda has proven effective MORE said on Sunday that it's getting more difficult for him to stick to the pledge he made to support the eventual Republican nominee.
"Look, I’ll be honest with you: It’s getting harder every day. It really is," the Florida senator said on ABC's "This Week" Sunday, referring to supporting front-runner Donald TrumpDonald TrumpThe Hill's 12:30 Report Poll: Clinton leading by 6 in Nevada Ex-Miss Universe responds to Trump's sex tape allegations MORE.
Rubio said he knows people are angry and frustrated, but those in positions of leadership need to show these people "a way forward that gives them hope and a belief that we can make things better.
"That's real leadership," he said.
"That’s not what we’re getting from the front-runner," he added.
Rubio said he isn't going to change his position about supporting the nominee because he still believes Trump will not secure the nomination.
"I’m going to do everything possible to keep that from happening and to give the party a choice in me," he said, "someone that people aren’t going to have to be asked that question about."