President Donald Trump nominated Kavanaugh to replace retired Justice Anthony Kennedy.
Sen. Claire McCaskill is one of a few red-state Democrats, whose vote could be critical in whether Kavanaugh joins the nation's highest court. She is also one of a few Democrats who met with Kavanaugh.
Confirmation hearings are set to begin Tuesday when his confirmation hearing starts, but Democrats in the Senate already are miffed about the process after the White House refused to release more than 100,000 pages of documents.
The documents, which relate to Kavanaugh's time as a lawyer for the George W. Bush administration, were to be used in the Senate hearing.
[Related: Where does Kavanaugh stand on key issues?]
Missouri Attorney General Josh Hawley, who is the Republican nominee running against McCaskill in the November general election, believes Kavanaugh is more than qualified.
"Show some leadership, show some backbone, pledge to vote for Kavanaugh. Stand up to your party and say you all need to support him too," Hawley said in a recent statement.
McCaskill spoke with 41 Action News the day before meeting with Kavanagh last month.
"Our courts have been a haven for the little guy to have a shot and that's what I'm looking at right now in his opinions," she said at the time. "How many times has he heard the argument of the little guy and decided that that's the side he wanted to be on?"