It's an old theory about Ontario politics — that voters tend to elect provincial governments of a political hue different from the one running the show in Ottawa.
It's also one of those rare instances in politics of the conventional wisdom being (mostly) right.
It is impossible to say whether this pattern — one party in power federally, another party in power in Queen's Park — is by design or merely coincidence. But it isn't a two-way street. While the pattern bodes ill for Kathleen Wynne's Liberals in the June 7 provincial election, you can't really draw any conclusions from it about Justin Trudeau's re-election chances in 2019.