The New York State Senate on Tuesday night expelled a senator convicted of assaulting his companion, the first time a member of the Legislature was forced from office in nearly a century.
Hiram Monserrate, a Democrat from Queens, was convicted last fall of misdemeanor assault after a fight with his companion, Karla Giraldo, that left her with a deep gash on her face, though he was acquitted of more serious felony assault charges.
Rather than bringing a close to Mr. Monserrate’s legislative career, the expulsion could be the beginning of a lengthy fight that would play out in the courts and create further instability in the already volatile political atmosphere in Albany.
As the Senate moved forward with a vote, Mr. Monserrate’s lawyers were drafting a temporary restraining order seeking to have him reinstated. One of the lawyers, Norman Siegel, said the order would be filed Wednesday in federal court in Manhattan.
“This case raises substantial questions concerning what a constitutional democracy is all about,” Mr. Siegel said. “The New York State Senate does not have the constitutional and legal authority to expel Senator Monserrate. And even if they did, their actions have not been consistent with due process of law.”
The expulsion followed roughly five hours of closed-door negotiations among Senate Democrats, though Mr. Monserrate was asked to leave the room for part of the deliberations.
“Nobody was happy about this,” said Senator Eric T. Schneiderman, the Manhattan Democrat who led the special committee that recommended that the Senate consider expelling Mr. Monserrate. “But most senators on both sides of the aisle felt that we had to do something. The days of sweeping things under the rug are over.”
Few other episodes have so grimly symbolized Albany’s reputation as a place where impropriety and ethically questionable conduct among public officials is commonplace.
As a member of a fragile Democratic majority that holds power by a single vote, Mr. Monserrate used the threat that he would switch political allegiances to gain considerable leverage within his party. After he was arrested in December 2008 and details of the assault became known, no Democrats in the Senate openly criticized his conduct. He was given a committee chairmanship, though it was revoked after his indictment, and was even the beneficiary of a fund-raiser by the majority leader at the time, Senator Malcolm A. Smith of Queens.
In June, Mr. Monserrate was one of two Democrats who took part in the upheaval that temporarily resulted in the party’s loss of power in the Senate. His formerly loyal colleagues quickly turned on him.
Democrats lashed out: Mr. Smith’s spokesman called Mr. Monserrate “a thug,” and some Democrats began openly questioning whether he was fit to hold office.
Yet a week after the coup, Mr. Monserrate agreed to abandon his alliance with Republicans and was welcomed back into the Democratic fold. He was given back his committee chairmanship, along with its $12,500 stipend.
But once his trial ended in a misdemeanor conviction, the tide turned against Mr. Monserrate once again. Senator John L. Sampson, the Democrats’ leader, convened a special committee in October to look into the assault and determine whether it merited any disciplinary action from the Senate.
Last month the committee issued a lengthy report that castigated Mr. Monserrate, saying that he showed little remorse for injuring his companion and that he was more interested in preserving his political standing. The committee found that Mr. Monserrate’s actions demonstrated he was unfit to serve, and it recommended that the full Senate vote on a resolution to remove him from office. That report, completed on Jan. 13, set the wheels in motion for the vote Tuesday.
Though no provision in the State Constitution grants explicit authority for the Legislature to expel its own members, state law does. Still, expulsion has been extremely rare. The last time it occurred was in the 1920s, when six assemblymen who were members of the Socialist Party of America were kicked out of office.