"I got along with everybody. You get along with nobody. You don't have one Republican senator ... backing you, not one. You don't have the endorsement of one," the party front-runner told Cruz during CNN’s GOP presidential debate. 
"You should be ashamed of yourself," he added. 
The Texas senator responded that he makes enemies because he stands up for his beliefs.
"You know, I actually think Donald is right: He is promising if he is elected, he'll go and cut deals in Washington, and he's right," he said, mentioning Trump's donations to Democrats.
He said the billionaire businessman gave more than $50,000 to those pushing for the 2013 Gang of Eight immigration bill.
"Donald funded the Gang of Eight," Cruz said. 
"In 2013, when I was leading the fight against the Gang of Eight amnesty bill, where was Donald? He was firing Dennis Rodman on 'Celebrity Apprentice,' " the Texan added.
Trump picked up his first two congressional endorsements this week. Cruz has more than two dozen endorsements from lawmakers in the House, but none from senators.