A 30-second ad with celebrities pressuring Republican members of the Electoral College to vote against Donald Trump is running just two days before the Electoral College casts its vote on Monday, Dec. 19.
A coalition of outside groups is spending $500,000 to run the ad in all 50 states.
The ad, featuring celebrities like Martin Sheen and Debra Messing, started running Saturday and will run Sunday as well, according to USA Today.
The ad is sponsored by the groups Unite for America and Americans Take Action.
The ad starts with Martin Sheen saying, "Republican members of the Electoral College, this message is for you."
The ad cites The Federalist Papers and tells electors that their job is to ensure "that the presidency only goes to someone who is to an eminent degree, endowed with the requisite qualifications."
Some celebrities like Patton Oswalt and Jenna Ushkowitz voiced their support.
All 538 members of the Electoral College will meet Monday in state capitols to cast their votes for president. The group gathered outside the Lincoln Memorial in Washington, D.C., calling themselves the "Hamilton Electors" and urging electors to block Trump from the presidency.