WASHINGTON — Here’s the thing about impromptu moments in politics: Often they work, sometimes they fall flat, but occasionally they turn out downright awkward. Vice President Joe Biden learned that the hard way Tuesday — twice.

Hosting a White House summit on violent extremism, Biden sought to draw a parallel between Minneapolis, where local leaders are working to prevent radicalization of Somali youth, and his hometown of Wilmington, Delaware, which Biden said also has a “large, very identifiable Somali community.”

“I might add, if you ever come to the train station you may notice that I have great relations with them, because an awful lot of them are driving cabs, and are friends of mine,” Biden said.

His audience — a group of religious and community leaders, many of them Muslim or of African descent — responded with muted, uncomfortable chuckles as Biden continued without skipping a beat. “For real. I’m not being solicitous, I’m being serious,” he said.

To some, the observation smacked of a well-publicized gaffe that then-Sen. Biden made in 2006, when he told an Indian-American supporter that in Delaware, “you cannot go to a 7-Eleven or a Dunkin’ Donuts unless you have a slight Indian accent.” Amid the resulting dust-up, Biden’s aides said he simply meant to highlight the vibrant Indian-American community in his home state.