Social media has brought down a second NDP candidate in the Saskatchewan election.

A screen grab circulated by the governing Saskatchewan Party shows a Facebook post that says "Brad Wall's mother should have taken the abortion pill."

Mark Jeworski, who was running in Weyburn-Big Muddy against Health Minister Dustin Duncan, resigned Friday.

Charles Smith, a political science professor at the University of Saskatchewan, says he's surprised this is still happening.

"The first thing any candidate or party should be doing, before they sign off on nomination papers, is to be vetting social media accounts for disturbing content or politically damaging content," said Smith.

"That clearly didn't happen in these cases and it's really just surprising that we still have to talk about it in 2016."

Smith says it's possible that a party doesn't have enough resources to check out candidates.

There could also be a lack of awareness by some candidates who forget that what they've said on social media doesn't go away, he said.

"There should be some self-reflective questions, too, like why are you posting very disturbing content online? Why are you saying, quite frankly, very inappropriate things, sexist things?" said Smith.

A day earlier, Saskatchewan NDP Leader Cam Broten removed a candidate in Saskatoon due to questionable posts on Facebook.

One of the candidate's posts circulated by the Saskatchewan Party shows a photo with the words: "A true gentleman holds the door for his woman then smacks her ass." Above the image is written: "True, ladies?"

Broten says he doesn't tolerate inappropriate comments on social media.

But the NDP leader also says he doesn't think this will be a trend where people will continue to be pressured by their past use of social media.

"I don't think anyone wants this campaign to spiral down into a thing where it's trolling through Facebook and Twitter accounts and finding every example of a bad joke (or) off-coloured statement," Broten said at a campaign announcement Friday in Saskatoon.

Wall, who was also in Saskatoon, said candidates are vetted.

"The Internet's a big place and so it's difficult to know for sure you've found everything or seen everything," said Wall.

"I think this is a fact of life in society today. If you were applying for a job or I was applying for a job, I'd expect there to be due diligence by the company."

Candidates in other provinces have had social media posts come back to haunt them.

Earlier this month, a Manitoba Liberal candidate resigned for using derogatory terms to refer to women on social media. In a tweet dating back several years, Jamie Hall asked whether a whore can truly be a whore if no one hears her scream.

In the Alberta 2012 election, the Wildrose party was derailed by an Edmonton candidate who urged gays to repent or face an eternity in hell's "lake of fire" in online posts.

Smith says losing candidates could hurt the NDP in those constituencies and what happened may "linger" in the minds of voters.

"In terms of votes on voting day, I'm not sure it makes a huge difference, but it does contribute to a narrative of a campaign," he said.