MANCHESTER - Marco Rubio faced withering criticism of his readiness to be president and his policy depth in the last Republican debate before Tuesday's New Hampshire primary, as New Jersey Gov. Chris Christie and other candidates launched an aggressive campaign to slow the Florida senator's rise.

Rubio's responded with an uneven performance that could hurt his bid to emerge as a more mainstream alternative to Donald Trump and Texas Sen. Ted Cruz.

If anything, his weaker showing gave new hope to Christie, Jeb Bush and John Kasich, all of whom need strong finishes in New Hampshire to keep their White House bids afloat.

Fresh off his victory in the Iowa caucuses, Cruz also faced criticism for controversial political tactics, with one candidate disparaging him for having "Washington ethics."