RALEIGH, N.C. — Marching from the campus of North Carolina State University to the mall at the state Capitol on Thursday, opponents of a proposed constitutional ban on gay marriage were hoping to make their largest public show of support so far in the last southeastern state without such a provision in law.

The turnout, which Raleigh and State Capitol Police estimated at around 300, fell short of the 1,000 expected by organizers, underscoring the challenge that opponents face less than two months before the May 8 vote.

"A lot of people think North Carolina is a lost cause being in the Southeast, but North Carolina is a pretty progressive state," said Scott Heath of Honest NC, the group that organized the "Ides of Love" march.

Last year, lawmakers in the Republican-controlled General Assembly voted to approve a referendum that would amend the state constitution to say, in part, "Marriage between one man and one woman is the only domestic legal union that shall be valid or recognized in this state."

Supporters of the referendum say marriage is not a right, and the amendment would protect the traditional institution of marriage from court rulings allowing same-sex couples to wed. A call to Tami Fitzgerald, chairwoman of the committee leading the pro-amendment Vote FOR Marriage NC, was not immediately returned Thursday.

Opponents of the measure say it would enshrine discrimination in the state's constitution and could have unforeseen consequences in other aspects of law including domestic violence protection orders, which supporters deny.

"It's really simple: This isn't about being gay or being straight. This is about being equal," march organizer Cory Livengood said. "I'm not different than you or your daughter or your son or your brother or your mother in that I deserve the same rights anyone else does."

The march, for which Raleigh police blocked off portions of Hillsborough and Morgan streets, attracted a crowd diverse in age, including college students, retired people and those who took off work for a day. A festive atmosphere prevailed, with people waving American flags and blowing noisy plastic vuvuzela horns.

Erin Gaynor, a self-described "suburban housewife" from Cary, was showing off the running shoes she wore for the 2-mile trek, along with a text from her daughter saying, "I'm proud of you, mom."

That's not a unanimous opinion in her house: Gaynor's husband is in favor of the amendment, she said, but amending the state constitution strikes her as a needlessly radical step.

"I'm a registered Republican, but I just can't fathom a constitutional amendment about this," she said. "I hope people look long and hard at the ramifications of this."