Story highlights Grayson is running in a divisive primary against the more centrist Rep. Patrick Murphy

In February, Reid endorsed Murphy and called Grayson to drop out of the costly race

Washington (CNN) There was already bad blood between Sen. Harry Reid and Rep. Alan Grayson. But at a closed-door meeting on Capitol Hill Wednesday, things got really ugly when the Florida Democrat -- who is running for a Senate seat -- confronted Reid only to be shut down and told by the top Senate Democrat he hopes Grayson loses his primary race.

Grayson, one of the most liberal House Democrats, is running in a divisive primary against the more centrist Rep. Patrick Murphy to fill outgoing Sen. Marco Rubio's seat. In February, Reid endorsed Murphy and called Grayson to drop out of the costly race, citing allegations that he unethically promoted his Cayman Islands hedge funds while serving in Congress.

But Grayson, who is furious the Democratic establishment is working against him, decided to use Reid's visit to the Congressional Progressive Caucus's weekly lunch to confront him and call him out. According to members in the meeting, it got awkward when the third-term lawmaker stood up and repeatedly asked if Reid knew his name. Grayson told reporters afterward that Reid replied that he didn't know who he was.

Grayson then demanded that Reid provide evidence to back up complaints about his business dealings, and Reid responded that he thought the reports about his hedge fund were true and bluntly told him in front of a room full of uncomfortable Democrats, "I want you to lose."

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