While momentum (the results in one state carrying over to the next contests) has not been a very strong pattern so far in the GOP nominating fight, it seems to be showing some strength in recent weeks. The succession of states where Romney has won is probably lowering the resistance of some Republican voters to his candidacy. After undergoing a rough patch in head-to-head matchups with President Obama, Romney’s numbers have improved a bit in the last week, and he now trails Obama by 4 points.
For much of the campaign season, Romney has pointed to his electability in a general election matchup with Obama as an argument for his candidacy. When Romney fell 10 points behind in that head-to-head matchup, it became easier for more conservative GOP voters to vote their hearts (for the non-Romney candidate of the moment) than to fall in line for Romney.
Of course, if Santorum holds on in Tennessee and Ohio on Tuesday, and also wins in Oklahoma as he is expected to do and perhaps wins the caucuses in North Dakota and/or Alaska, he could claim to be the candidate with momentum coming out of Super Tuesday. But the chances of that scenario playing out began to collapse when Santorum lost his lead in Michigan, and seem to be dropping each day since then. Santorum must now hope to hold off what seems to be a rising tide for Mitt Romney in the most highly contested states on Tuesday of Ohio and Tennessee or Romney will begin to create some real distance between himself and the other candidates, and make his nomination again seem inevitable.
Tennessee and Ohio are the states that could break the dam of the conservative resistance to Romney.