Whether New York state Senators Stephen Saland of Poughkeepsie and Roy McDonald of Saratoga County will prevail in their GOP primary races remains uncertain.

Saland and McDonald were among the four Republicans who last year crossed the aisle to vote with all but one Democrat to legalize gay marriage in New York, making it the most populous state yet to do so.

Senator Mark Grisanti of Buffalo won his primary with a comfortable margin. James Alesi of Rochester, the fourth senator, retired.

Election officials began counting absentee ballots on Thursday. Saland's lead grew as more ballots were counted, The New York Times reported. But McDonald fell further behind. Some counties will not begin counting paper ballots until next week.

Opponents of marriage equality had vowed to take down the four senators.

(Related: Gay marriage foes target New York lawmakers with billboards.)