Gov. Martin O'Malley is set for a victory lap today when he signs into law his hard fought measure to legalize same-sex marriage. The signing is set for 5 p.m. in the State House.

A marriage bill came within a whisker of passage in 2011, but was shelved in the House of Delegates at the last minute when leaders determined they were a few votes shy. Securing those "few votes" this year took up much of the first 45 days of Maryland's General Assembly's legislative session.

Though both the House and the Senate chambers are dominated by Democrats, same-sex marriage was not an easy sell for the Democratic governor. In the end, two House Republicans bucked their party and voted for it -- ensuring passage. The Senate wrestled with the issue last year, and passed it with less drama this time.

But even with the governor's signature, same-sex couples won't get Maryland marriage certificates until the law goes into effect in January 2013 -- at the earliest.

Fired-up opponents have pledged to collect 100,000 signatures opposing the bill by June 30 -- about twice what they would need to trigger a state-wide referendum on the topic. On Wednesday several powerful groups joined forces to accomplish that goal.

Polls show that Marylanders are evenly split on the issue -- so there's no telling what will happen in November.