Calvin Coolidge once said that "persistence and determination alone are omnipotent."

The fact that Councilman Bill Green is sharing a plate of Memphis nachos with his wife, Margie, on a breezy Sunday afternoon in Chestnut Hill is proof that the 30th president of the United States was right – even when it comes to Philly Democrats.

The empty nesters get to talking about the night in 1986 when they caught each other's eye at the Hippodrome in London, where Green had fled to escape the massive shadow of his father, who served as congressman, mayor and head of Democratic City Committee.

Green started to make his way across the dance floor to the American woman in the green dress, but his friend got there first and asked her out on a date. Undeterred, Green says he then "arranged to be" at the same location where Margie and his backstabbing pal were meeting for drinks.

"I think today maybe they call it 'stalking,'" Margie Green says in her disarming Southern drawl as she soaks up the sun at Chestnut 7 on Germantown Avenue. "He was really rude and obnoxious, and he made fun of my accent."

They ended up meeting for tea and punting – a boat ride using a pole to push off the riverbed – and Green turned on the charm. Or, as he puts it, "I grew on her like a fungus."

So what happened to Green's buddy who tried to put the moves on his future wife?

"The bad part for Margie...," Green says with a chuckle. "We read in the paper a few years ago that he's worth about $40 million."

With their children, Avery and William, at college, the Greens kick back on Sundays in their sleepy nook of the city. He dutifully takes his daughter's hyperactive, yet obedient, poodle for a walk through Pastorious Park, directly across the street from their home.

Asked if he'll run for mayor in 2015, Green chooses his words carefully, knowing he'd have to resign as councilman if he publicly declared his candidacy.

"I think I'm the only person who has a plan, knows what to do on Day 1 and would not be afraid to execute it," Green says.

That's not a formal announcement, he adds. But he's looking quite mayoral as he walks down Germantown Avenue.