From "boy scout" to "Premier Dad" to now "the uncle no one wants to talk about."

So it goes for Ontario Premier Dalton McGuinty, who has run the largest province in the country for nine years, and who decided this week to step down before his party totally implodes.

The conventional wisdom is that politicians know when it’s time to go. But the one-time Ottawa lawyer may have overstayed his welcome by a year.

After back-to-back majority governments, McGuinty reached for number three in 2011. He returned to the premiership last October with a minority, and with a tag that — for many voters in Ontario — his best before date had expired.

McGuinty’s first two terms in 2003 and 2007 were marked by major achievements: there were heavy investments in education and health care, support for the troubled auto industry, a push to green energy, and the activation of environmental protection measures.

But since that October election night, McGuinty has struggled to deal with what he liked to call his "major minority" — a term that has come to mean no truck or trade with the opposition — though there have been some minor agreements along the way.

Basically, the leaders of the opposition parties complain McGuinty has operated as if he still had his majority — a "my way or the highway" approach to governing that clearly irked the Progressive Conservatives and New Democrats.

Minority governments of yore worked well in Ontario. Former PC premier Bill Davis was able to find common ground with then NDP leader, Stephen Lewis, in successive minority governments in the 1970s.

The parties didn't agree on every issue. But they agreed enough for the Tories to survive not once, but twice, and Davis was rewarded in 1981 with a majority government.

Ontario Premier Dalton McGuinty embraces wife Terri after announcing Monday that he is resigning. (Michelle Siu/Canadian Press)

The difference is clear. Davis was prepared to seek co-operation and compromise.

Dalton McGuinty? Confrontation. And the result of that short-sighted approach is that he’s now leaving, having failed to make his government and its agenda work.

Kitchener-Waterloo loss a harbinger

McGuinty and his party were sent a clear signal just over a month ago by voters in the riding of Kitchener-Waterloo.

Not only was the Liberal candidate in the byelection there defeated, he finished in third place behind the NDP and the PC candidates.

Initially, the result was viewed as just one more anti-government byelection. But in the long term, it may well have marked the beginning of the end of McGuinty — a message that it was time to go.

For many years McGuinty enjoyed the total support of his caucus. After all, big election wins and the perks of power had a tendency to quell even his most outspoken critics.

But toward the end, many Liberals were talking privately about the need for McGuinty to go and that he had worn out his welcome.

There was chatter that the government had lost its way, mired in scandals at provincial agencies and politically motivated infrastructure decisions that made a mockery of McGuinty’s oft-stated commitment to "protecting taxpayers' money."

McGuinty’s downfall serves as a textbook example of what happens to governments that stay in power for several years: they forget they once sat on the other side of the legislature. They forget they had to struggle to get noticed by voters and the media and that they were sent to Queen's Park to represent voters, not their own interests.

It’s the arrogance of power — if nothing else — that has left the Liberals in search of a new leader and a new way.

Polls haven't been offering much good news for the Liberals and the opposition smells blood. And so the hustings beckon for a provincial election campaign that may well give Ontario what McGuinty couldn't anymore — a new government.