The Trump campaign probably needs to put a stop to this, for the sake of political hygiene if nothing else.

Trump’s campaign already denounced the robocall, which is an indication they’re learning how to handle Duke. When the former Klan leader and has-been political gadfly initially attempted to tie himself to Trump, the latter attempted to play the resulting controversy off by pretending not to even know who he was. That didn’t work, and it fed the media narrative that Trump was courting the white supremacist vote. Trump did denounce Duke then, but the denunciation came late and wasn’t credited as such.

So now, the rejections come more quickly and are more forceful.

Donald Trump’s campaign disavowed a robocall from Louisiana Senate candidate David Duke in which the former Ku Klux Klan grand wizard urged voters to “stand up and vote for Donald Trump for president and vote for me, David Duke, for the U.S. Senate.”

“Mr. Trump has continued to denounce David Duke and any group or individual associated with a message of hate,” the Trump campaign said in a statement to POLITICO. “There is no place for this in the Republican Party or our country. We have no knowledge of these calls or any related activities, but strongly condemn and disavow.”

What’s going on here is obvious. Duke perceives that the rise of Trump as the nominee and the stealth mainstreaming of the alt-right as a piece of the Republican electoral coalition gives him a pathway, via Trump, into the political mainstream after he’s spent some 40 years on the fringe – and he also correctly perceives that the media won’t be able to resist giving him coverage when he ties himself to Trump.

That when they do so they’re fueling Hillary Clinton’s new narrative that Trump is a Klansman without the hood is not a particular problem for David Duke. It would be charitable to say David Duke is not particularly a political team player. If he were to do Trump damage while benefiting the fundraising apparatus he’s disguising as a campaign, that’s OK by him.

What’s striking here is the level of cynicism and disdain for the voting public Duke displays, of course – cynicism and disdain he’s always had. He knows tying himself to Trump hurts Trump, and he knows he’s not wanted in the Republican Party whose ideals he says he embraces (but doesn’t). But he thinks there are enough unsophisticated, pissed-off voters he can rally to his side to become relevant (and most importantly to raise money from) if he can just find something shiny to show them, and here’s Trump whose rhetoric is just close enough to some of the things Duke has said to qualify.

And therefore Duke gloms onto Trump at every opportunity.

Duke isn’t a major problem for Trump, because Duke isn’t a major anything. He’s a grifter, a con man whose day came and went 25 years ago. He’s reasonably good at earning media attention only because putting him on TV helps the Democrats smear the GOP as racist, and he’s shameless enough to oblige them. Duke doesn’t have any credibility, and therefore stunts like this robocall don’t really move anybody’s vote.

But if Trump were to make an endorsement of some other candidate in the Louisiana Senate race it could put Duke to bed; even Duke couldn’t try tying himself to Trump when Trump had already repudiated him not only personally but by backing a John Kennedy, John Fleming, Rob Maness or Charles Boustany.

Which of those to endorse is a good question, though, because none of them quite seem to be a great fit for Trump.