"There's a lot more interaction, physical interaction," says Judd Gregg, the former New Hampshire senator who helped President George W. Bush prepare for debates.
Trump gets softballs at town hall ahead of Clinton showdown →
"I think both Ted Cruz and Donald Trump create very serious issues for us in the general election," Mr. Gregg said. "We probably have the weakest Democratic candidate in decades running in Hillary Clinton, so it is unfortunate."
Republican voters prove cool to John Kasich's electability pitch →