Sen. Marco Rubio is stepping up his attacks on Ted Cruz and Chris Christie, signaling he sees them as his main competition in emerging as the the alternative to Trump. He attacks Cruz as soft on national security, and Christie for having once supported the Common Core among other liberal ideas:

‘He has voted for and supported a containment budget that would reduce national security. I think we need to rebuild the U.S. military,’  Mr. Rubio told CNN. ‘He is in favor of weakening our intelligence programs. I am in favor of strengthening and expanding them.’

Mr. Rubio’s stops in Iowa Tuesday coincided with the release of a new ad from Conservative Solutions PAC, a group backing him, that accused Mr. Christie of embracing many of the same policy positions as President Obama.

‘Chris Christie could well be President Obama’s favorite Republican governor,’ the narrators says in the ad. ‘Chris Christie: One high tax, Common Core, liberal energy loving, Obamacare Medicaid expanding President is enough.’

Mr. Rubio defended the ad, saying the accusations it makes are ‘true.’

‘This country cannot afford a president that’s not going to reverse the direction that Barack Obama has taken our country,’ Mr. Rubio told CNN between campaign stops in Iowa Tuesday, alluding to Mr. Christie. ‘We can’t have another president that supports Common Core or gun control or expanding Obamacare.’

Maggie Gallagher is a senior fellow at the American Principles Project.