Together, the quartet comprises only a tiny fraction of the nearly 2,400 governors who have served in U.S. history, according to records from the National Governors Association.
The gap between electing African-Americans to Congress and taking their campaigns to the state level has been a big one. The 1965 Voting Rights Act helped usher more minorities into office by mandating the creation of majority-minority legislative districts, and African-Americans currently make up 10 percent of Congress, close to their 13 percent share of the country's overall population. But some argue that such districts isolate black politicians from the broader coalitions they would need to make the jump to statewide office.
John Walsh, a Patrick adviser who currently runs the Massachusetts governor's Together PAC, said "I've met Brown. He's a very talented person, and I think one of the things that's so important about him and candidates like Deval Patrick is that they don't run in a historic context. They're not asking voters, 'Elect me as the first African-American governor,' but putting forward a set of values and ideas that appeal to all voters."
Brown's campaign manager, Justin Schall, echoed Walsh's sentiment. "I think anybody's background plays a large role in their story," he said. But he added: "We want people to vote for him because he has the best ideas."
The scant attention paid to Brown's chance to become his state's first black governor may be in part due to the fact that Maryland has a better track record of electing African-Americans to federal office than any other state. This is partly because Maryland's population is 30 percent black, a greater share than any state outside the Deep South, where racial politics can be more polarizing.
That's not to say Brown's unique position is entirely absent from his campaign. The Iraq War veteran and former state delegate has woven two issues into his campaign that disproportionately affect African-American communities — domestic-violence prevention, and adoption and foster parenthood.
For Brown, these issues are personal. His cousin Catherine was killed by an estranged boyfriend in 2008, and he adopted his son Jonathan with his first wife in 2000. Despite a busy campaign schedule, Brown still makes time to attend Sunday church services across the state to promote adoption.
Virginia's Wilder, who became the nation's first elected black governor in 1989, believes that, overall, "attention has been somewhat diverted" from building a pipeline of black leaders by President Obama's successes. Obama's presidency distracted many people from the dearth of rising African-Americans elsewhere and the significant roadblocks they still face, he said.
Wilder's choice piece of wisdom has long been this: "Being first isn't worth a dime if there isn't a second." It's a line Walsh, Patrick's former campaign manager, recalls the then-Richmond mayor delivering when he traveled north to stump for Patrick in 2006. And this year, Wilder is committed to ensuring there's a third. Recalling a conversation with O'Malley at Terry McAuliffe's inauguration in January, Wilder said: "We had a pretty long talk about Anthony."