1. Multiple prolife candidates (4 in these cases) all fighting each other for the same base votes means a candidate who's not prolife (Rick Snyder) can sweep in, get the moderates and some conservatives and win. Candidates who have no chance of winning (I'm thinking Mike Bouchard and Tom George) should drop out once they realize they can't win or else they're just taking votes from the other prolife candidates and allowing the non-prolife candidate to win.
2. Letting a non-prolife candidate with no political experience and millions of dollars define himself is a mistake. Throughout the campaign for governor, Rick Snyder was able to use his personal fortune to define himself as a savvy businessman and a "tough nerd" who had a plan for getting Michigan back on track. I never once saw an ad by one of the more conservative candidates informing Republican primary voters that Snyder was more moderate than the other candidates on social issues. My guess is that there were thousands of Michigan voters who voted for Snyder assuming that he was prolife.
3. Spending millions to attack a nine-term conservative congressman as not being conservative enough in his own uber-conservative area is dumb. Instead of educating primary voters about the moderate, non-prolife candidate in the race, Mike Cox and various organizations who supported him wasted untold amounts of money trying to out-conservative Pete Hoekstra. This was a complete waste of resources in West Michigan. Hoekstra has been serving his conservative district well for 18 years. People in the 2nd Congressional district know and respect Pete Hoekstra. The Christian Reformed Church members in Ottawa county aren't suddenly going to turn their backs on the man they've voted for 9 times because he missed some Congressional votes while campaigning for governor.
Since Snyder's positions were hardly mentioned or attacked, he looked above the fray. He was able to just keep plugging away with his positive message.
A Detroit Free Press poll taken in late July showed that Snyder (26%) had a very slight lead over Cox (24%) and Hoekstra (23%). The poll of likely Republican voters showed that about 16% were undecided. On election day, Snyder finished with 36% of vote, getting approximately 2/3 of the undecideds.