Lapsed Democrat Bloomberg says he’s backing Clinton,

Michael Bloomberg, who bypassed his own run for the presidency this elec- tion cycle, will endorse Hil- lary Clinton in a prime-time address at the Democratic convention and make the case for Clinton as the best choice for moderate voters in 2016, an adviser to Bloomberg said.

The news is an unexpected move from Bloomberg, who has not been a member of the Democratic Party since 2000; was elected the mayor of New York City as a Republican; and later became an independent.

But it reflects Bloomberg’s increasing dismay about the rise of Donald Trump and a determination to see that the Republican nominee is defeated.

Clinton is seeking to reach out to middle-of-the-road swing voters and even moderate Republicans uneasy about Trump. Polls show that significant numbers of Republicans remain wary of Trump and question his fitness for the presidency.

Bloomberg will vouch for Clinton “from the perspective of a business leader and an independent,” said Howard Wolfson, a senior adviser to Bloomberg.

“As the nation’s leading independent and a prag- matic business leader, Mike has supported candidates from both sides of the aisle,” Wolfson said. “This week in Philadelphia he will make a strong case that the clear choice in this election is Hillary Clinton.”

Bloomberg, who has been sharply critical of Trump’s views on immigration and the economy, may fortify Clinton’s appeal to the political center.

And with the Republican nominee basing his campaign on his background as a businessman, Bloomberg, a billionaire media executive and philanthropist, may help counter the Trump sales pitch.

It is unusual, but not unheard of, for a speaker who is not a member of a political party to address that party’s convention.