The Arizona Republic said Paul supporters booed and shouted down Romney's son, Josh, and other pro-Romney speakers at the Phoenix convention where delegates to the national convention in Tampa were being elected.
The younger Romney urged voters to unite against President Obama; however, he had to stop speaking repeatedly as noisy Paul fans disrupted the proceedings.
Romney saluted his father's challengers for the nomination, all of whom but Paul have formally dropped out of the race. "I recognize how hard it is to run for president, the sacrifice those men and women made running for president," he said. "It's a great contribution they've made to the party."
The Republic said Romney closed by urging all Republicans to get behind his dad; however, that elicited jeers from the pro-Paul members of the audience.
Arizona is a winner-take-all primary state for the Republicans. Relations between the state and the party's national leadership was strained when the GOP reduced Arizona's delegate count from 58 to 29 in response to the rescheduling of the Arizona primary in violation of party rules.