A political tail wind boosting their prospects, Republicans have significant opportunities to gain governorships across the Great Lakes and Midwest this fall. But, in a wrinkle to their coast-to-coast victory plan, the GOP is struggling with internal fights in a handful of primaries, giving Democrats hope of snatching a few big states.

The outcome of a whopping 37 races will determine control of several heavily populated states ahead of the decennial redrawing of congressional and legislative boundaries. The census decides who will have the advantage in the quest for control of statehouses and Congress over the next 10 years.

And many governors elected in November will preside over states certain to loom large in President Obama's likely 2012 re-election bid...