Rubio's moment -- and more scrutiny -- has arrived

Strategists say Rubio should take Bush’s slights — and Trump’s too, for that matter — as a good sign. “That’s a compliment to Rubio and his organization: He’s on the radar screen,” says Katon Dawson, a former South Carolina party chairman who was backing Rick Perry before he dropped out. Dawson, who campaigned for former president George W. Bush, said he has not yet decided whom he will now support, but has a preference for governors.

While Trump and Carson continue to lead in the polls, there is an opening for someone to emerge on the establishment-oriented, economic-conservative side, a lane occupied by Bush and Rubio, as well as John Kasich and Chris Christie.

“There’s a real battle going on for the consensus center-right candidate in the party, and among the folks who are vying for that, there’s greater activity and more elbowing,” says Gross, the Iowa Republican. “Rubio has some momentum — not enormous, but some — and Bush’s interest is to make sure no competitor maintains that level of momentum when it comes time for the caucus.”

With Scott Walker now out of the race, the competition in that lane has become particularly competitive, and it has helped Rubio rise. It’s that development that gives Bush cause for concern.

“Rubio has got himself that seat at the table,” says one GOP strategist in Iowa. Voters interested in candidates in that mold “know Jeb is going to be there, he’s like the safety school, but there’s now this notion of ‘Let’s see if this young guy Rubio is the real deal.’”