If memory serves, the debates prior to the New Hampshire primary in 2008 were brutal attacks by the rest of the field on Mitt Romney. Rubio should expect similar treatment tonight, which may be one of the key tests of whether he has what it takes to be the party’s nominee. Christie and Bush will come at him hard, and Cruz and Trump have the incentive to hit him, too. One question is whether Rubio can parry effectively while not getting dragged into extended mud fights and elevating enough to deliver his core message of party unity and uplift.
Meanwhile, since no ever seems to pay much attention to Kasich, who is possibly competing for second in New Hampshire, he is the one who is likeliest to do what he needs to do for his own purposes tonight.