A new American Research Group poll of February 28th’s Michigan Republican primary, conducted completely after former Senator Rick Santorum’s wins in the Minnesota and Colorado Republican caucuses, shows him with a six point lead in the Great Lakes State. Santorum gets 33 percent of Republicans polled, with former Massachusetts Gov. Mitt Romney, whose father was governor of Michigan and was where he grew up, second with 27 percent. Former House Speaker Newt Gingrich gets 21 percent and Rep. Ron Paul (R-TX) sees 12 percent.

Going further into the numbers, ARG’s analysis points to voting bloc that’s been the most key this cycle – the very conservative bloc:

Santorum leads with 37% among likely Republican primary voters saying they are supporters of the Tea Party, followed by Gingrich with 29%, Romney with 17%, and Paul with 11%. Among likely primary voters saying they are not supporters of the Tea Party or are undecided about the Tea Party, Romney leads with 35%, followed by Santorum with 30%, Gingrich with 14%, and Paul with 13%.

The current TPM Poll Average of the Michigan Republican primary shows a dead heat between Santorum and Romney.