It also exemplified the increase in gay political muscle that has helped lead to historic victories at the polls and in the court of public opinion for lesbian, gay, bisexual, and transgender citizens.
"I was motivated," Heifetz, 77, said of his contribution to Priorities USA Action, known for a series of scathing TV ads that attacked Mitt Romney's career in private equity.
"For the gay community, the first four years of Obama were probably the best four years we've ever had," Heifetz said. "We started to receive more of our rights than we had under all the previous administrations."
Not only did Obama appoint a record number of gays and lesbians to federal posts, he ended the "don't ask, don't tell" rule that kept homosexuals from serving openly in the military. And, of course, the president eventually endorsed legal same-sex marriage, at some political risk.
More broadly, the cause of gay rights and the acceptance of LBGT people in the United States are advancing faster than Heifetz could have imagined when he was a younger man tangling with a certain hard-nosed police captain named Frank L. Rizzo.
Voters in Maine, Maryland, Minnesota, and Washington state supported the right to same-sex marriage in referendums; now, nine states and the District of Columbia have legalized such unions. Wisconsin elected the first openly gay U.S. senator, Democrat Tammy Baldwin; six openly gay candidates won House seats. And the Supreme Court has agreed to hear two cases that could profoundly affect the legal definition of marriage.
Most polls find a plurality or slight majority of Americans now support marriage rights for same-sex couples. Among younger people, the number is higher - 73 percent of those 18 to 29 who responded to a Dec. 5 Gallup poll.
In the world of political money, Heifetz may not be as well known as the Koch brothers or George Soros, or Pennsylvania mega-donors such as John M. Templeton and Richard Mellon Scaife.
But he has given to politicians who are friendly to gay rights and to some political action committees, including Emily's List, which supports female candidates - a total of $108,000 in federal contributions in 2011-12 - and is a steady, if quiet, source of help for nonprofits around Philadelphia, particularly those that help people with AIDS.
Twice in recent years, Heifetz has made news for large acts of activist charity. In 2005, he spent $274,000 to retire the mortgage of the William Way LGBT Community Center. And he offered to buy the city-owned Boy Scouts building on Logan Square for up to $2 million to help settle litigation that resulted when the city tried to evict the scouts for their national policy of excluding gays. The city lost a lawsuit and had to pick up $963,575 of the scouts' legal bills; city officials offered to sell the building to the scouts to meet that debt, but gay activists objected. The issue is pending.
"It's not that I think the building was worth it, but I was willing to buy it just so that the scouts didn't have it," Heifetz said. "Then in the first week, we'd hang the biggest gay flag over the front of that building . . . only to say, 'We won, we won.' " (He had planned to donate the building to charity eventually.)
And though he has become an insider among gay political donors - invited, for instance, to join the Gill Organization, the Denver group founded by software magnate Tim Gill to bankroll and strategize in the state-by-state fight for marriage rights - Heifetz has stayed mostly under the radar.
He has attended White House receptions with hundreds of other Obama supporters but says he has not received any special access or favors, aside from an arty print of a limited-edition campaign poster sent by the folks from Priorities USA as a thank-you. Heifetz said he does not need anything from the government.
His real estate empire consists of dozens of apartment and townhouse rentals across Center City, and the Alexander Inn, a boutique hotel at 12th and Spruce Streets that he and his company rehabbed. A native Philadelphian, he began buying properties when he was in his 20s, not long out of the Army.
"Mel is a self-made man, the type of guy who will literally roll up his sleeves and work alongside his handymen," said Malcolm Lazin, president of the Equality Forum, a Philadelphia LGBT civil rights group that holds an annual international festival.
"I have not known him to ever ask for anything in return," Lazin said. "He turns down perks that most other people would do backflips over. For instance, Mel was offered VIP access at the Democratic convention and turned it down. He gives for the right reasons. . . . He's really an unsung hero."
Former Gov. Ed Rendell said he first met Heifetz while campaigning in gay bars during his race for district attorney in 1977. (At the time, Heifetz owned some.) Heifetz has been a strong supporter of Rendell's since.
"He . . . leads by example," Rendell said. "I wasn't surprised when I heard about the $1 million, because Mel has always been one for backing up his beliefs with action. Like many gay and lesbian Americans, he felt like it was a significant threat if the other side won - not necessarily from Mitt Romney personally, but from the people in the Republican Party who were setting the agenda."
Now that people are hearing about the $1 million, Heifitz, who shares a condo on the Delaware River with his longtime partner and who has a second home in Miami Beach and is registered to vote there as an independent, finds himself bombarded with solicitations for political causes.
He still plans to help candidates he believes in, but can't at this point imagine writing another $1 million check - unless "circumstances require it." He saw the risk of Obama's losing as too high; he wrote in an essay for the Huffington Post that a Romney victory would "take us back to the 1950s."
That was the decade when Heifetz began his activism. In 1959, a coffeehouse he owned at 21st and Sansom Streets, the Humoresque, was raided by police officers under Rizzo's command.
Heifetz was charged with "running a disorderly house," based on neighbors' complaints of rowdiness, noise, and the presence of same-sex couples - labeled suspected "sex perverts" in some news accounts in those days.
He was convicted of the disorderly charge. He sued the police, and Rizzo personally, for violating his civil rights. He lost, but began a lifelong association with the American Civil Liberties Union.
Heifetz has said he believes his coffeehouse was singled out for police harassment because he didn't pay bribes in an era when bar shakedowns were not uncommon.
Being a young gay man was not easy back in the day.
"It was like being in a private, secret society," Heifetz said. "Gay bars used to be on a dark street with one light lit or something, and you knocked on the door and the door'd open. . . . All the bars used to pay off the police - because [homosexuality] was held in such disdain and they knew they could coerce money."
His anger flares when he thinks of the AIDS epidemic, of how some on the religious right called it God's punishment, and about the hundreds of friends he has known who devotedly cared for sick partners, unable to be married or to have their love acknowledged by society.
"It leaves you marked," he said.
And yet, he has more hope than ever.
"It usually takes a lot of generations to see substantial changes in anything," Heifetz said. "For the gay community, we have seen so much change in a 30- or 40-year period, it is just cosmic - it's just really beyond belief."
Contact Thomas Fitzgerald at 215-313-3099, email@example.com, or follow @tomfitzgerald on Twitter. Read his blog, "The Big Tent," at www.philly.com/BigTent.