Marisol Alcantara

Democrats' chances of reclaiming New York's state Senate suffered a major setback on Tuesday night, and for the most revolting reason possible: A supposed "progressive" who won a primary for an open seat on Manhattan's West Side has promised to join a group of renegade Democrats who side with the Republicans and keep the GOP in power even though it holds a minority of seats in the chamber. Since this district is safely blue, Marisol Alcantara, a union organizer and—if you can believe it—a vocal Bernie Sanders supporter, will become the sixth conspirator in this traitorous junta, known as the Independent Democratic Conference.

And make no mistake about it: The IDC exists solely to further the power of its members. Its leader, Jeff Klein, struck a dirty bargain with the GOP years ago, becoming "Co-Leader and President Pro Tempore" alongside Republican Dean Skelos. (Skelos has since been sentenced to five years in prison for corruption.) From that perch, while earning perks for himself—such as a custom-gerrymandered home district—Klein and the IDC have helped Republicans stymie boatloads of progressive priorities.

That includes things like a state version of the DREAM Act, which would allow undocumented immigrants to receive college tuition assistance. The IDC professes to support it, but their GOP allies refuse to let it come up for a vote. If Democrats were in charge, it would pass tomorrow. The IDC knows this, and that makes them worse than hypocrites.

And it's this gang of power-hungry self-promoters that Alcantara, who won with just 33 percent of the vote, will soon be a part of. Stunningly, a spokesperson for Alcantara claimed that she's "as progressive as they come," but there is nothing progressive about supporting the IDC—and the Republican Party. It's almost unfathomable that Alcantara would even do such a thing, but it starts to make a little more sense when you learn that, after she entered the race late, the IDC spent heavily on her behalf.

Now her craven move means that mainstream Democrats would need to pick up seven Republican-held seats this November in order to take back the Senate and not have to worry about Klein and his band of sellouts. That's a daunting task, though Democrats should be able to make some gains on Election Day. If they do, and the IDC continues to prop up the GOP, it will make the IDC's ongoing efforts to thwart the will of New York's Democratic majority even more egregious. Is that where Marisol Alcantara really wants to find herself?