Former Republican presidential candidate Jeb Bush has endorsed Texas Senator Ted Cruz for president, calling him a "principled conservative".
Mr Bush, the former governor of Florida, dropped out of the race last month after poor showings in state contests.
He says Mr Cruz has shown the ability to appeal to voters and win primary contests, as in Utah this week.
Republicans must "overcome the divisiveness and vulgarity" Donald Trump has introduced, he said.
Otherwise, the party will certainly lose the White House to Democratic front-runner Hillary Clinton, Mr Bush wrote in a Facebook post.