CLEVELAND, Ohio - "Elephants have long memories."

That’s the message former New York City Mayor Rudy Giuliani had for Ted Cruz after the Texas senator’s refusal to endorse Donald Trump during Wednesday’s speech at the Republican National Convention in Cleveland, Ohio.

In his primetime address, Cruz told Americans to "stand and speak and vote your conscience." He didn’t relent to boos and chants of "endorse Trump" and "say his name," instead finishing up his speech and exiting the stage.

Giuliani remarked Thursday that Cruz, who dropped out of the presidential race in May, had promised to endorse whomever won the Republican nomination for president.

"I was taught in politics and in life a man's word is his bond. Ted Cruz broke his word, which means there are serious questions about Ted Cruz," Giuliani said. "Republicans, remember, are represented by the elephant. Elephants have long memories. We’re not going to forget this."