Executive editor Fred Barnes discussed Tuesday's tightest and most significant congressional primary races with the Wall Street Journal's Mary Kissel.

Florida senator Marco Rubio "came back from losing the presidential race and then big-footed his way into the race." He's up against Carlos Berruff, but "he's still very, very favorably regarded among Florida Republicans," and Donald Trump's dismal polling in the state is not affecting Rubio at all, Barnes said.

Meanwhile the former chairwoman of the Democratic National Committee Debbie Wassermann Schultz faces off against Tim Canova in Palm Beach Country for Wasserman Schultz's House district. "It'll be tough for Tim to win," said Barnes. "You know he's been endorsed by Bernie Sanders. Sanders had, at least as of yesterday, had not come to campaign for his in the district. And I'll have to say Debbie Wassermann Schultz, who has alienated a lot of Democrats, she clearly tilted the Democratic National Committee when she headed it in favor of the Hillary Clinton in the primaries—but then Hillary Clinton won by better than two to one in her district."

Meanwhile in Arizona, senator John McCain's primary challenger Kelli Ward doesn't help herself when she targets her opponent's age, said Barnes, who added he doesn't think Ward's efforts will be effective.

"Here's something he learned from earlier primary challenges, and that is to take them very, very seriously. And he does. And on the other hand, Kelli Ward has not really gotten support from some of these groups like the Club for Growth that tend to support dissident republican candidates. So McCain all in all looks like he's in pretty good shape."