Because of the rules of distribution of delegates in the Michigan primary, Rick Santorum and Mitt Romney found themselves in a tie game with both receiving 15 of the state's 30 delegates.
That was before the state party voted to change the rules after the fact.
Late last night the Michigan Republican Party voted to change the rules so that Mitt Romney would receive the two delegates previously split between the two candidates.
Michigan’s two at-large delegates to the Republican National convention will be awarded to Michigan native Mitt Romney, following a vote last night by the state party’s credentials’ committee.
The vote came despite the party’s rules that the two at-large delegates are supposed to be awarded on a proportional basis based on the statewide popular vote. Romney won the statewide vote by a 41% to 38% margin over former Pennsylvania Sen. Rick Santorum. [...]
As a result, Romney gets 16 delegates and Santorum 14.
In the grand scheme of things this probably won't dramatically alter the outcome of the race, however it does some highly unethical and shady to change the rules after the voters have already spoken.
State party officials voted to give the win to Romney just because they can. I'm sure the base will really love that.