In an unusual power-sharing agreement that ought to be remembered should Andrew Cuomo ever try to run for President, Republicans and a group of “independent Democrats” will share control of the New York State Senate, despite Democrats running on the Democratic ballot line winning as many as 33 of the 63 seats in the chamber.

The power-sharing deal announced Tuesday was a victory for New York Republicans, who are outnumbered 2-to-1 in the state’s electorate and who fared unexpectedly poorly in a series of Senate races last month. The exact outcome of the election remains unclear, because ballots in two close races are still being counted, but the consensus in Albany is that the Democrats won more seats than the Republicans.

But shortly after the elections, one Democrat said he would align himself with the Republicans, and on Tuesday five others said they would join with the Republicans to control the Senate. Many of the remaining Senate Democrats were furious, accusing the Republicans and the breakaway Democrats of orchestrating a coup to steal control.

As part of the deal, the Senate majority leader, Dean G. Skelos, a Long Island Republican, agreed to share authority over the chamber with Senator Jeffrey D. Klein, a Bronx Democrat who was the No. 2 official in his caucus before defecting nearly two years ago to form the Independent Democratic Conference.

The Independent Democratic Conference will become a new, third party in the state Senate, and the GOP and IDC will trade off control every couple weeks, literally a handover between Skelos and Klein. Democrats will remain in the minority.

Lots of villains in this sad story, but first you have to question the New York state Democratic Party for allowing six candidates to run on their ballot line and then break away from their party after the election. These included “independent Democrats” from Brooklyn and Queens, areas with huge Democratic majorities, where clearly a Democratic candidate willing to vote for a Democrat to lead the Senate could have been found. That probably should be the first question on the “so you want to run as a Democrat for state Senate” questionnaire.

But while this was happening, Andrew Cuomo, nominally the Democratic governor, not only failed to enforce control on the situation by demanding that the Democrats hold with their party, but pretty much stayed out of the matter, playing it off as “internal legislative business.” Not only that, Cuomo endorsed Republicans in several state Senate races in 2012. Apparently, the deal was run by Cuomo before the announcement.

I think the first problem here falls on the state Dems. But of course, Cuomo is the leader of the party. It’s clear that he didn’t want a Democratic majority in the state Senate, which occurred largely by accident, because that would put pressure on him to advance measures like public financing and an increase in the minimum wage. I don’t know that the “independent Democrats” would have necessarily voted for those measures, but I’m told by people with knowledge of the situation that they would have had less bargaining room under a Democratic Senate.

There’s probably not a more dysfunctional legislative chamber in America than the New York state Senate. But Andrew Cuomo’s treachery here should be duly noted.