Three Republican governors declined to sign a letter supporting Supreme Court nominee Brett Kavanaugh, according to The Associated Press.

GOP governors from 30 states and two territories wrote a letter to Senate leaders asking that they move "expeditiously to confirm" President Trump's pick to replace Justice Anthony Kennedy.

"Judge Kavanaugh's impeccable credentials demonstrate he is worthy of this nomination," the governors wrote.

The letter was not signed by GOP Govs. Charlie Baker (Mass.) Larry Hogan (Md.), and Phil Scott (Vt.), the AP reported. Bruce Rauner (Ill.) signed the later after initially indicating he would not.

The letter is part of a coordinated campaign from the White House to strengthen support for Trump's second Supreme Court pick, after Justice Neil Gorsuch, according to the AP.

Senate Majority Leader Mitch McConnell (R-Ky.) has said Kavanaugh's confirmation vote will come this fall, ahead of the November midterms and potentially before the Supreme Court begins its next term in October.

Republicans hold a 51-49 majority in the Senate, and Kavanaugh's confirmation hearings are expected take place in September amid an effort by Democrats to sink his nomination - or at least delay a confirmation vote until after the midterm elections in November.

Kavanaugh has spent the past 12 years as a judge on the nation's second most powerful court: the U.S. Court of Appeals for the District of Columbia Circuit. He has authored more than 300 opinions while serving in that role, and Democrats have said they want to inspect all documents pertaining to Kavanaugh, including those from his time in the George W. Bush White House.

-Updated 2:05 p.m.