Missouri Sen. Claire McCaskill announced Wednesday that she will not support Judge Brett Kavanaugh’s nomination to the Supreme Court. 

In a statement posted on Twitter, the Democrat attributed her decision mostly to the nominee’s positions on “dark, anonymous money that is crushing our democracy.”

“While I am also uncomfortable about his view on Presidential power as it relates to the rule of law, and his position that corporations are people, it is his allegiance to the position that unlimited donations and dark anonymous money, from even foreign interests, should be allowed to swamp the voices of individuals that has been the determining factor in my decision to vote no on his nomination,” McCaskill said

Kavanaugh’s nomination has been rocked by allegations that he sexually assaulted Christine Blasey Ford at a party when the two were in high school in the 1980s. McCaskill said she did not base her decision on the allegations, which she said were “troubling and deserve a thorough and fair examination by the Senate Judiciary Committee.” 

McCaskill is one of the most vulnerable senators running for re-election this year. Her Republican opponent, state Attorney General Josh Hawley, has made the Supreme Court vacancy a centerpiece of his campaign. 

Hawley said McCaskill’s decision was not a surprise.

“Claire McCaskill is now 0 for 6 on Supreme Court nominees since she started running for the Senate 12 long years ago,” he said. “She has sided with Chuck Schumer every single time — for liberals and against Missouri. Senator McCaskill has forgotten where she’s from and become just another Washington liberal.”

Inside Elections with Nathan L. Gonzales rates the Missouri Senate race a Toss-up. 

Watch: Hirono on Kavanaugh Accusation — Men Need to “Shut Up and Step Up”