Chip DiPaula, former Gov. Robert Ehrlich's chief of staff, is one of the highest profile Republicans in the state to add his voice to the pro-gay marriage cause. (Doug Kapustin/TWP)

A decade ago, Chip DiPaula Jr. was the architect of Robert L. Ehrlich Jr.’s unexpected victory as Maryland’s first Republican governor in a generation.

Today, he is part of something that might seem just as unlikely: a political alliance with the Democratic governor who ended Ehrlich’s tenure. DiPaula has been working alongside Gov. Martin O’Malley since this summer on the campaign to uphold Maryland’s same-sex marriage law.

It is a cause, DiPaula says, that transcends partisan politics — and for him is personal.

“The current governor and I don’t agree on a whole lot of other issues, but you know what? That’s beside the point for me,” said DiPaula, who talked openly for the first time in a media interview about being gay. “I’m involved to make our lives better.”

DiPaula is not on the cusp of marrying anyone himself but said he greatly respects the institution, and he has officiated at the weddings of a few straight friends and family members.

“I would like to be able to experience that joy in my life,” he said.

DiPaula, 50, who served as Ehrlich’s budget secretary and chief of staff after running his 2002 campaign, is part of a group of advisers that is plotting strategy for the same-sex marriage referendum on the November ballot. He has been involved in fundraising efforts as well, co-hosting an event last week in the District with O’Malley and Mayor Vincent C. Gray (D).

DiPaula’s decision to join an effort dominated by Democrats not only speaks to his pragmatism, friends say. It also underscores a reality of the campaign not often discussed: Winning will require Republican votes.

Recent polling has shown proponents of Question 6 with a lead, but one modest enough that support from Democrats alone will probably not carry them across the finish line next month. The campaign entered a new phase this week, with opponents airing the first television ads arguing that “no one is entitled to redefine marriage.”

DiPaula and other Republicans onboard in Maryland — including Ken Mehlman, a former Republican National Committee chairman — counter that same-sex marriage is consistent with GOP principles of individual liberty and strengthening families. But that is not the prevailing view among party luminaries, including Ehrlich, who has been outspoken in his opposition.

“One redefinition will most assuredly beget additional redefinitions: Why not a civil right to more than one spouse?” Ehrlich, who now pens a column for the Baltimore Sun, wrote in April. “Where does one draw the line once the traditional threshold is crossed?”

DiPaula said he considers Ehrlich a friend but was let down by the column, as he was on a couple of occasions during his tenure as governor.

“I continue to hope that he can continue to evolve on the issue,” DiPaula said during an interview over lunch in Annapolis, where he works as an executive at a global marketing company. “The denial of that right makes for two tiers of society, and it means that government says we have two classes of people.”

Ehrlich denied repeated requests for comment on this story.

By 2002, DiPaula, a Towson University graduate and Baltimore native, was making a name for himself in Republican circles nationally. In 2000, he managed the GOP national convention in Philadelphia.

After defeating Kathleen Kennedy Townsend in 2002, Ehrlich asked DiPaula, whom he had known for years, to be his budget secretary as the state was facing a gaping fiscal hole. Two years later, DiPaula moved over to chief of staff.

In Annapolis, he developed a reputation as someone fiercely loyal to Ehrlich but who was willing to engage in a give-and-take with Democratic legislators at a time when they were adjusting to divided rule. And he was often good-natured about it.

DiPaula, a Catholic, came out as gay to his family and friends a few years earlier, while in his mid-30s. His orientation wasn’t exactly a secret in Annapolis — Ehrlich “absolutely” knew, DiPaula said — but it was something he did not talk about publicly.

“Part of my discretion was if you’re serving a governor, it’s all about him,” DiPaula said.

He said he suspects talking about his sexuality now will not come as news to many people, something that his friends aren’t as sure about.

“If I can paraphrase Jerry Seinfeld, I’m over 40, I’ve never been married and I’m neat,” DiPaula said with a shrug. “Go figure.”

There were times when DiPaula was disappointed in Ehrlich. In 2005, Ehrlich vetoed a bill that would have granted nearly a dozen rights to gay partners, including medical decision-making authority, if they registered with the state. Ehrlich argued that the registry was a threat to “the sanctity of traditional marriage.”

DiPaula said he concluded it was better to work within the system than to abandon it, and Ehrlich did help advance some gay rights issues. The year after vetoing the registry bill, for example, he supported a more limited measure expanding rights, and he had a solid record of appointing gay judges, DiPaula said.

Though he cannot legally marry in Maryland himself, DiPaula is an authorized nondenominational Christian minister and has officiated at the weddings of a few family members and friends.

In 2010, he officiated at the marriage of two longtime Democratic staffers: Kristin F. Jones, chief of staff to House Speaker Michael E. Busch (D-Anne Arundel), and Joseph C. Bryce, chief lobbyist for O’Malley.

Both developed deep friendships with DiPaula during his days with Ehrlich, and both were central to the effort to pass a gay nuptials bill during this year’s legislative session.

DiPaula played a behind-the-scenes role in the legislative debate, lobbying several Republican lawmakers. (One senator and two delegates voted for the bill.)

As part of the referendum campaign, DiPaula has helped reach out to Republican funders and national groups and brought a more business-oriented approach to the task, others involved say.

“He’s helped open doors we thought were closed,” said Del. Maggie McIntosh (D-Baltimore). “He’s smart. He’s strategic. And he’s fun. He’s added a great perspective.”