Many liberals are adamant there is no threat of voter fraud that justifies efforts to improve the integrity of elections. “There is no real concrete evidence of voter fraud,” tweeted Donna Brazile, former acting chair of the Democratic National Committee, this week. “It’s a big ass lie.” James O’Keefe, the guerilla filmmaker who brought down the ACORN voter-registration fraudsters in 2010 and forced the resignation of NPR executives, politely disagrees.

Today, he is releasing some new undercover footage that raises disturbing questions about ballot integrity in Colorado, the site of fiercely contested races for the U.S. Senate, the U.S. House, and the governorship. When he raised the issue of filling out some of the unused ballots that are mailed to every household in the state this month, he was told by Meredith Hicks, the director of Work for Progress, a liberal group funded by Democratic Super PACS.: “That is not even like lying or something, if someone throws out a ballot, like if you want to fill it out you should do it.” She then brazenly offered O’Keefe, disguised as a middle-aged college instructor, a job with her group.

Colorado secretary of state Scott Gessler, along with several county election clerks, have raised warning flags that a new state law that automatically mails a ballot to everyone is an engraved invitation to commit fraud. “Sending ballots to people who did not even ask for them or have moved out of state is asking for trouble” he told me. For example, little can stop someone who collects discarded ballots from trash cans, fills out the ballots, and mails them in. Election workers are supposed to compare signatures on registration records with signed ballots. But if a person has a “witness” who signs the ballot on the witness line, then the signatures do not have to match and the vote is counted.