"Terri Lynn Land is a dedicated and accomplished public servant and the type of woman we need to put forward more often in the Republican Party. I strongly endorse her candidacy and urge Republicans across the state to unite behind her," Miller said in a statement released by Land's campaign. "She will serve our great state well in the United States Senate."

Miller is close with Reps. Dave Camp (R-Mich.) and Mike Rogers (R-Mich.), who were heavily courted by Republicans for the race but decided against running for the Senate.

Her endorsement is a signal that the party establishment will look to rally around Land, a candidate many state Republicans view as competent but few are excited about. 

Democrats have united around Rep. Gary Peters (D-Mich.) to replace Sen. Carl LevinCarl LevinSilencing of Warren another example of hyperpartisan Senate GOP going nuclear over Gorsuch might destroy filibuster forever Obama to preserve torture report in presidential papers MORE (D-Mich.), and Peters appears to have the upper hand.