With his surprise announcement that he's stepping down as premier of Ontario, McGuinty is suddenly free to run for the federal Liberal leadership if he so chooses.
If he does, he'll have a ready-made campaign team all set to go.
For the past month, a draft campaign has been in the works to persuade McGuinty to jump into the federal fray.
Sources say a leadership campaign road map has already been sketched out.
Some of his closest campaign advisers have been involved, including brother Brendan McGuinty — who was on hand for McGuinty's news conference Monday — and Don Guy, campaign director for each of McGuinty's three winning provincial campaigns.
Deputy chief of staff Dave Gene, former chief of staff Chris Morley and former operations director Charlie Angelakos are also part of the group.
"The core nucleus of the team that he's been able to build around him, that took him through three election campaigns, is a proven team ... It would be a ready-made team that would be able to focus on this [leadership] as well," said one insider close to McGuinty.
McGuinty has not yet decided whether to take the plunge, those close to him insist, but he is feeling the pressure.
"I don't think he's changed his mind yet," said one close associate. "But I can tell you that some of this is getting to him."
On Monday night, McGuinty ducked the question about possibly entering federal politics.
"We have no plans with respect to our future," McGuinty told reporters.
"I am not making any plans whatsoever beyond my duties here at Queen's Park."
The movement to draft McGuinty has been fuelled by a sense of urgency that the race needs a heavyweight contender to challenge presumed front-runner Justin Trudeau, eldest son of former prime minister and Liberal icon Pierre Elliott Trudeau.
McGuinty's supporters insist the draft movement isn't aimed at stopping the Trudeau juggernaut so much as ensuring that there is a real, competitive, vigorous race that tests the mettle of the eventual winner, whomever that turns out to be.
"I think there is a strong recognition that the party does need an exciting race with a lot of different candidates in it if we're going to rebuild and move forward," the insider said.
Those involved in the draft campaign insist McGuinty would be a strong contender: a three-time winning premier in the country's largest province, someone with experience fending off the Conservative attack machine, rebuilding a decimated party and grappling with all the major public policy issues.
As one put it, McGuinty's capabilities would be "a good contrast to the way the race is developing right now."
The 40-year-old Trudeau is perceived in some quarters as being long on celebrity but short on depth. He is nevertheless the party's undisputed rock star. His entry into the leadership race last week has vaulted the Liberals ahead of the NDP, according to at least one opinion poll.
Ironically, one of Trudeau's top campaign strategists is Gerald Butts, a former senior adviser to McGuinty.
Ruled out running federally in the past
McGuinty has in the past repeatedly ruled out running for the federal Liberal leadership.
"I want you to know; I love my country but I am committed to my province and my party," he told a provincial Liberal gathering last November, after his brother, Ottawa MP David McGuinty, mused about the premier as a potential federal leadership contender.
Indeed, it has long seemed unlikely that McGuinty would give up being premier of the country's largest province to vie for the leadership of a federal party that was reduced to a humiliating 34 seats and third party status in the 2011 election.
However, those close to McGuinty maintain he wouldn't be put off by the dismal state of the federal Liberals. The provincial Liberals were in a similarly sorry state when McGuinty took the helm 16 years ago, they note.
"There's a lot of analogs between what he started with in 1996 and the federal situation today," another insider said.
"That's not daunting to him."