In case you didn’t spend the weekend following political news, Republican presidential nominee #Donald Trump spent the last four getting into a pissing contest, and losing it, with the Muslim father of an American soldier who died fighting for his country.

#Khizr Khan is the father of U.S. Army Capt. Humayun Khan, who was killed while fighting in Iraq in 2004. At the Democratic National Convention, in probably the most memorable and powerful moment of either convention, the elder Khan denounced Donald Trump’s proposed Muslim ban, while holding up a book of the U.S. Constitution and declaring “You have sacrificed nothing- and no one.”

Trump, ever unable to avoid responding to a slight, fought back in a series of interviews and tweets, bashing him as “emotional,” before questioning whether Khan’s wife, who had stood by him during the speech, was “allowed” to speak, which is rich coming from a candidate whose wife is known for standing to his side and almost never speaking. The candidate continued digging, to the denunciations of just about everyone, including the likes of Paul Ryan and John McCain, therefore turning an embarrassing one-day story into a much worse five-day one.

It gets worse

That there would eventually be an ugly smear campaign about the Khan family was inevitable, and it arrived Sunday night, in the form of an article published on the website of rightwing anti-Muslim extremist Walid Shoebat, with the bylines of Shoebat himself and his son, Theodore Shoebat. The piece alleges that “What The Media Is Not Telling You About The Muslim Who Attacked Donald Trump: He Is A Muslim Brotherhood Agent Who Wants To Advance Sharia Law And Bring Muslims Into The United States,” and also argues that Khan’s son, the dead soldier, was also secretly an agent of jihad.

And then, soon after, Roger Stone -- Trump’s longtime political consigliere who currently advises the candidate informally, tweeted Shoebat’s article to his nearly 70,000 Twitter followers.

What’s notable is about the article isn’t so much that Shoebat is a proven fraud- CNN exposed him in 2011 as having invented his entire background as an “ex-terrorist.” Or that the opening paragraph ends with the line “Trump we have your back.” What’s shocking is just how comically short it falls of proving its case.

The argument that Khan is an agent of the Muslim Brotherhood is that he… lived in “Saudi Arabia, the motherland of Wahhabism, which means that Khan clearly had a Wahabist connection.” No, that’s not what that means. It also lists an academic paper that Khan wrote 30 years ago that cited the late Muslim Brotherhood leader Said Ramadan, and notes that Khan is now an attorney who works on immigration law.

That’s literally it. That’s all they got. No evidence that Khan has a secret mission or connections to any foreign government. Just pure conjecture. And even uglier is the insinuation -- once again, completely without a scintilla of evidence -- that Khan’s son died not as an heroic solider but as agent of jihad.

This is something of a perennial tactic of the most blog-based anti-Muslim movement, one that’s been applied to virtually every prominent American Muslim at one point or another: fifth-generation guilt by association. This person knows someone who knows someone who went to some mosque or knew some imam who knew someone else who once maybe appeared on a government watch list, assuming it was the same “Muhammad Abdul,” but we’ll just go ahead and assume it was. And people believe it, every time.

It’s ugly, hateful, and absolutely un-American. And it must be denounced by everyone, from Donald Trump on down. #Election 2016