"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 Milton LevinSen. Gillibrand, eyeing 2020 bid, rankles some Democrats The Hill's 12:30 Report Congress needs bipartisanship to fully investigate Russian influence MORE (D-Mich.), and Peters appears to have the upper hand.