Advocates

Penned in by blue velvet ropes just outside the House chambers, the two women stood with their backs to each other as reporters closed in.

They knew each other, but didn't say hello. They had work to do. And besides, they are on opposite sides of perhaps the most divisive issue in Massachusetts politics. Arline Isaacson supports same-sex marriage, while Evelyn Reilly opposes it.

After their interviews, Isaacson stood 2 feet from Reilly and flipped open her cellphone. After a pause, with reporters watching for any interaction, the lobbyists laughed.

"Should we give them the scandalous pictures?" Isaacson quipped.

Reilly laughed, and the women quickly parted ways.

It was the only time they interacted, as Isaacson, cochairwoman of the Massachusetts Gay and Lesbian Caucus, and Reilly, public policy director of the Massachusetts Family Institute, scoured Beacon Hill yesterday, on the eve of a potentially historic vote on a constitutional amendment to ban same-sex marriage.

After months of lobbying and strategizing, they were in the last hours of trying to sway the handful of legislators who will decide the outcome.

Just before 11 a.m., in her jumbled office near the State House, Isaacson talked on the desk phone as her cellphone began to vibrate on a nearby chair.

Isaacson peered over her reading glasses at a typewritten master list, a purple sheet with five columns of names. The first column listed lawmakers she considered on her side. It was the longest. But the fifth column, the ones she would not even try to lobby, was the next longest.

She later delivered copies of the list to the offices of Governor Deval Patrick and House Speaker Salvatore F. DiMasi, who have also been trying to steer legislators to vote against the measure today and kill the amendment.

"It'll be a disaster if this goes to 2008," Isaacson said. "The ramifications nationally are so severe for the Dems and the Repubs."

About the same time, Reilly arrived at the State House and within 10 minutes a television crew lit up her face.

"That's my best side," she said with a glowing smile.

"You have no bad sides," the reporter responded.

Reilly -- dressed in a royal blue blazer, dark skirt, and white beads -- admitted that she used to be extremely shy. At 5 feet 2 inches, she is far from intimidating, but she has been a soldier in her movement for 30 of her 66 years.

She isn't the one who is usually in front of the cameras representing same-sex marriage foes, but yesterday Reilly had to fill in.

"Today, backup is on deck," she said.

"Paul!" Isaacson exclaimed.

Across the marble hall, Representative Paul C. Casey turned from the lobby door. Casey, a Winchester Democrat who plans to vote for the amendment banning same-sex marriage, playfully ducked behind a column, and Isaacson weaved toward him. They hugged.

A television crew swooped down on the unlikely pair. So did a guard, who reminded Isaacson to stay on her side of the blue velvet rope, the boundary for lobbyists.

"This is a legislator who thinks things through," Isaacson told the camera crew. "He's fair, and he's reasonable."

"That's the beauty of both sides," Casey responded.

"It's important to leave no stone unturned," Isaacson said.

A crowd of restless schoolchildren parked themselves near the House chambers. A legislator sliced through the tour group to meet Reilly. The two backed away from the noisy children to talk business.

"This is what it's all about, the kids," said Reilly, watching the last child turn the corner. "What kind of world they are going to grow up in. . . . Little boys come home and say, 'Teacher told me I can marry Tommy.' That is so wrong."

With few legislators roaming the halls, she took a short coffee break upstairs and saw a man walk by. She dug through her large black bag, finally pulling out a sheet of legislators' photos.

"OK, that's not he," she said.

By 1:45 p.m., Isaacson needed a soy protein shake.

The 52-year-old, who is on leave as a lobbyist for the Massachusetts Teachers Association, has been actively supporting gay rights for 25 years.

"The marriage issue is fundamentally a labor issue, though most people don't recognize that," she said. "Without a marriage license, you can't access some of the central employment benefits, bread-and-butter benefits."

She moves quickly, is direct when talking to legislators, and is known to use colorful language describing her political opponents. Her approach is to always be careful in counting votes.

"It's frustrating," Isaacson said, wearing a taupe skirt suit and 2-inch heels and holding the banister as she climbed the cramped stairs to the State House Cafe. "It's very frustrating because legislators keep upping the ante on what they want to get for their votes."

She pulled up a chair to a table with four legislators relaxing. One ducked out to answer his cellphone, another leaned back to talk to a man at a nearby table. She walked out for a private meeting with a third, a legislator she considered to be on the fence.

Reilly sat down for lunch in the State House cafe with Jonathan Ring, a 27-year-old volunteer, taking large bites quickly from her hot dog before the session resumed downstairs.

Four teenagers armed with packets of literature, interrupted, and Reilly instructed them to fan out and drop off their fliers at the remaining legislators' offices.

While she said her opponents have called her everything from homophobic to bigot, Reilly said she is trying to protect the institution of marriage.

"Every human being deserves to be treated with respect," she said. "But not all behavior is equally worthy."