It has little to do with underestimating him. Yeah, the "drama teacher" won a riding people said he would never win, won the leadership of a party people said was dead, and won an election people said he'd never win.
It's just people insisting on being unnecessarily snide and incapable of showing any respect to the country's institutions. Criticize him all you want (I do), but be a grown-up about it. And people should stop using a term that explicitly suggests that educators are somehow incapable.
Same goes for the other party leaders.
Trudeau taught drama, as well as math and French, ages ago. Not sure what the issue is with a PM that's actually been in a classroom (among other places). Harper was always a bit stiff -
he could have benefited from some drama training. Trudeau has long since moved on, confounded his critics and risen to the top political office in the land. It's pretty sad that that there are still people holding on the tired old "drama teacher" refrain. Anyone who actually cared about the Conservative Party and its future success would have dumped that loser shtick long ago.
We're not all angels. It's sometimes hard not to resort to names when an M.P. says something stupid, or takes a dumb, self-serving position on an issue. But the PM and the other party leaders represent high offices in our political system, not to mention parties and large constituencies among the population. We should all try to do better.