Despite an aggressive petition drive to force a referendum on the state's Dream Act — which allows in-state tuition rates for the children of illegal immigrants — the campaign to defeat the measure in November remains a low-budget, grass-roots operation without much evidence of an organized effort.

With the Nov. 6 election just a month away, opponents have yet to register a ballot committee with the State Board of Elections — typically one of the first steps in waging a high-profile referendum battle.

The measure's foes achieved a stunning success when Del. Neil C. Parrott mobilized an online petition-gathering operation after last year's General Assembly session and quickly rounded up enough signatures for a referendum. But the effort appears to have lost momentum.

"If we're going to do something, it needs to happen soon," said Parrott, a Washington County Republican. He said there will be more anti-Dream Act activity, but there are no firm plans yet.

The freshman lawmaker surprised veterans of Maryland politics with his ability to gather enough valid signatures to challenge the Democratic-backed legislation through his innovative site, mdpetitions.com. But now, with the efforts to defeat the law in the shadows, there are questions whether Republicans can back up their petition prowess at the ballot box.

Sen. Edward R. Reilly, an Anne Arundel County Republican who opposes the Dream Act, said grass-roots sentiment was "at a fever pitch" when volunteers fanned out around the state to collect signatures after the 2011 General Assembly session.

"Since it made it to the referendum stage, there is no umbrella committee that's organized and funded to promote it," Reilly said. "It's still a hot-button issue when I talk to people one-on-one, but there's nobody pushing for it."

Del. Michael Smigiel, an Upper Shore Republican, said he was surprised that there was no sustained campaign once the measure was placed on the ballot. Supporters of the law are "much more adamant and coordinated in their efforts," he said.

The fight over the Dream Act — and a similar effort to overturn Maryland's congressional redistricting map — have been overshadowed by the higher-profile ballot issues of same-sex marriage and expanded gambling.

Passions on the marriage issue are driven by competing views of morality, while interest in the gambling measure has been stoked by enormous spending by rival casino companies. Other issues have a hard time competing for attention.

A recent Baltimore Sun poll found that Maryland voters are almost evenly split on the Dream Act, which would extend in-state tuition to students who attend three years of high school in Maryland and whose families can show they have paid state taxes. Other polls have suggested a stronger majority in favor of the law.

The law also requires that students who take advantage of the provision attend community college for the first two years. If voters approve, Maryland would become the first state where such a measure has been upheld in a referendum.

Conservatives say they are gearing up to keep that from happening. But it appears they will have to play catch-up as they work to counter a campaign by supporters of the measure.

"The other side is very well-funded with government money," Parrott said. "It's not surprising that they're organized and on the street right now."

Kristin Ford, spokeswoman for Educating Maryland Kids, said the pro-Dream Act ballot committee has bought $54,000 in radio time in the Baltimore area. Ford said she expects the campaign to spend more than $1 million on paid media out of a total budget of about $1.5 million. The group is a broad-based coalition that includes labor unions, churches and the immigrant rights group CASA of Maryland, she said.

"We've had a lot of folks bring money to the table," Ford said. She said the pro-Dream Act group will begin running radio ads this week and will have ads on television from mid-October through Election Day. None of the money Educating Maryland Kids has raised comes from government sources, she said.

CASA political director Kim Propeack said the group receives government funds for social services it offers but uses none of that money for political advocacy.

On Saturday, CASA of Maryland plans a pro-Dream Act march from Langley Park to the University of Maryland, College Park that it expects will draw about 1,000. Opponents knew of no activities on a similar scale.

On each weekend until Election Day, the Maryland Industrial Areas Foundation plans to send clergy and lay people to churches, synagogues and mosques to press for votes for the Dream Act. Alisa Glassman, an organizer for the group, said the foundation has trained 540 people to act as advocates.

For now, the anti-Dream Act campaign centers around a website called Help Save Maryland, run by Germantown conservative activist Brad Botwin.