As Canadians, it’s easy for us to get swept up in U.S. politics (see: endless debates, “PRESIDENTIAL HARASSMENT!!!” tweets), but the reverse is rare and usually worth savouring.

So Twitter users expressed a very Canadian kind of surprise when former U.S. president Barack Obama tweeted his endorsement of Liberal leader Justin Trudeau on Wednesday.

“I was proud to work with Justin Trudeau as President. He's a hard-working, effective leader who takes on big issues like climate change,” Obama wrote in an instantly-viral tweet. “The world needs his progressive leadership now, and I hope our neighbors to the north support him for another term.”

The tweet went far beyond the other quote-unquote celebrity endorsements we’ve seen on social media this election, like Rihanna’s now-famous follow and DMs with the NDP’s Jagmeet Singh. Obama not only mentioned issues Trudeau gets behind, but labeled him a “progressive” leader who deserves a second shot.

Reaction was mostly shock and awe, but Conservative Twitter predictably chimed in with claims of foreign influence. “Canadians were worried about Russian interference, maybe Chinese interference. Looks like the foreign interference in our election was to be American!” tweeted pundit Stephen Taylor.

The tweet comes as polls place Trudeau neck and neck with Conservative leader Andrew Scheer. With only a few days left until the October 21 vote, and with some 5 million Canadians already voted, there's a lot of uncertainty in the air.

The tweet also drew critics of both leaders’ progressive credentials.

“The two of these men utterly failed to move the needle on both climate policy and the concomitant refugee crisis it's about to precipitate,” Maclean’s editor Andray Domise tweeted.

“Enjoy your retirement while the rest of us clean up the mess.”