Primaries page, makes it clear that the Republican primary has, as expected, broken along regional lines. Mitt Romney has the West and the Northeast; Rick Santorum tends to win the Midwest and South. But Santorum's competitors have scored wins in his regions: Romney has won some states in the Midwest, and Newt Gingrich has won two states in the Deep South. If this pattern continues, Romney's path to winning the majority of the delegates is clear. Santorum can't win a majority, and Gingrich can't come close.
For one of Romney's competitors to win the nomination, something fundamental has to change in the race. Santorum's plan, of course, is to change the race by beating Gingrich in the Deep South and driving him out of the race entirely. Once Gingrich is gone, Santorum will unify the Anti-Romney vote. Santorum hopes that this will increase his overall support enough to sweep the Midwest and maybe even pick off a state here or there in Romney's regions.
But suppose Santorum doesn't beat Gingrich in the few remaining Deep South states. Or suppose Gingrich refuses to withdraw from the race regardless. Is Santorum completely powerless to beat Romney? Perhaps. Santorum's back-up plan is to win enough momentum in the Midwest and South so that voters begin to doubt Romney's frontrunner status and change their minds about supporting him. For that plan to work, the calendar will need to favor Santorum.
Let's consider the remainder of the calendar, as broken down into the different regions: The West and Northeast (Romney's strongholds), the Midwest (a Santorum-favoring region into which Romney has been making inroads), the Deep South (Gingrich country so far, but maybe not so much if the voters become strategic), and the South (where Santorum should win).
Post-Super Tuesday March
West/Northeast (3): HI, PR, WY
Midwest (3): IL, KS, MO
Deep South (3): AL, LA, MS
West/Northeast (6): CT, DC, DE, MD, NY, RI
Midwest (2): PA, WI
Deep South (0):
West/Northeast (1): OR
Midwest (2): IN, NE
Deep South (0):
South (5): AR, KY, NC, TX, WV
West/Northeast (5): CA, MT, NJ, NM, UT
Midwest (1): SD
Deep South (0):
Different portions of the calendar favor different candidates. The remainder of March is a mixed bag. April heavily favors Romney. May heavily favors Santorum, and June also heavily favors Romney. Note that April, May, and June are the most important months, as most of the states are winner-take-all; prior to April most states award delegates proportionately.
What's the implication? It will be difficult for any candidate to build up much momentum. If Santorum does better than expected the rest of this month, he will still run into a wall in April, because the schedule is so unfavorable that month. April is great for Romney, but May will be a terrible month--on paper. In theory, Romney could build such a compelling case for himself during March/April that he's able to take Indiana and break into the Southern states. As it stands now, Romney would look like he's fading in May, and then sweep the rest of the states in June.