MANCHESTER, New Hampshire: 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 on Saturday night that could hurt his bid to emerge as an alternative to Donald Trump and Texas Sen.

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

Cruz, the Iowa caucuses winner, also took criticism at the debate for controversial political tactics, with one candidate disparaging him for having “Washington ethics” and being willing to test the campaign’s legal limits.

New Hampshire’s primary could further winnow an already shrinking GOP field or leave the primary muddled.

Hard-fought, expensive and far-ranging, the campaign has become a fight for the future of the Republican Party, though the direction the GOP will ultimately take remains deeply uncertain.