- Lindsey Graham is not getting behind Donald Trump
- Graham, who ran for president himself and dropped out last December, endorsed Jeb Bush for president, but the former Florida governor dropped out of the race as well
Graham told CNN he would choose to support the Texas Republican over the brash billionaire because Trump is an "interloper" and not a real Republican.
"Ted and I are in the same party. Donald Trump is an interloper," Graham said. "I don't trust him."
Graham said he believes Cruz represents a "form of conservatism that's hard to sell to the general public."
Graham, who ran for president himself and dropped out last December, endorsed Jeb Bush for president, but the former Florida governor dropped out of the race as well.
The senior South Carolina senator refused to say if he'd get behind Trump as the nominee.
"Ask me that after the convention. If he wins the Republican nomination, I will have to reconsider that," he said.
He also added that if Florida Sen. Marco Rubio and Ohio Gov. John Kasich lose their home states, they'll lose the momentum they need to beat Trump for the Republican nomination.
Fellow Sen. Cory Gardner of Colorado also told CNN that Kasich needs to get out of the 2016 race.
"There's no honorable mention in getting the nomination. John Kasich has run a good race ... But there's no path to victory for him," he said.