President Trump speaks during a campaign rally on Wednesday in Estero, Fla., at the Hertz Arena to help Republican candidates running in the midterms. (Joe Raedle/Getty Images)
Opinion writer

President Trump’s blatantly racist ad — showing an illegal immigrant boasting about killing police officers — is a fitting final pitch for a party and a campaign that are now nearly entirely focused on whipping up xenophobia. I won’t link to the ad; The Post describes it thusly:

The man on the screen has a shaved head and a mustache and long chin hair. Smiling, he announces, “I killed f‐‐‐— cops.”

The man is Luis Bracamontes, a twice-deported Mexican immigrant who was given the death penalty in April for killing two California law enforcement officers in 2014. At the time of the shootings, Bracamontes was in the United States illegally — and now, with the midterm election approaching, he’s the star of the GOP’s latest campaign ad. . . .

The text is superimposed over videos of Bracamontes appearing to show no remorse for his crimes, and even declaring, “I’m going to kill more cops soon.”

More footage follows: Throngs of unidentified people rioting in unidentified streets and pushing down fences in undisclosed locations. A Fox News Channel correspondent interviewing a man identified only as “deported immigrant in caravan,” who asks to be pardoned for attempted murder. … “Who else would Democrats let in?” the video asks. An image of Bracamontes smiling reappears before being replaced by text, “President Donald Trump and Republicans are making America safe again.”

To all the Republicans who think that words don’t matter, who rationalize support for the president because of judges or tax cuts, who insist that domestic terrorism is unrelated to normalization of virulent racist rhetoric and who remain silent believing they have no moral responsibility for this brand of politics, I would say this is reason enough to vote, as my colleague Max Boot has suggested, against each and every Republican on the ballot. We have not seen individual Republican candidates, let alone House and Senate leaders, denounce the ad or insist that Trump take it down. Silence is assent. And therefore each one deserves the ire of decent voters.

To all the White House staffers who think they are “saving” the United States from harm, who bristle at the notion they should be shunned from polite society (not harassed, shunned) and who insist that they be treated like staffers of previous administrations (e.g. thanked for their service), I would say that you will share the blame for a dark chapter in American history.

To Rupert Murdoch, Sean Hannity, Laura Ingraham, Lou Dobbs, Fox shareholders, Fox producers and Fox executives and other on-air Fox personalities, I would say that this is in large part your doing. You’ve spent years drumming up fear of immigrants, misrepresenting the danger they pose, blurring the line between criminals and noncriminals (including “dreamers”) and sending dog whistles — no, make that trumpet blasts — to the white nationalists. I would say to you that Fox is not a news organization but a source of material and affirmation for the worst elements in our society, a small sliver of whom become violent. It’s not a place where reputable news people should want to work, nor a network that advertisers should support or viewers should indulge.

I appreciate the condemnation of Republicans such as Sens. Jeff Flake (R-Ariz.) (“This is just a new low in campaigning. It’s sickening”), but they need to do more. It’s not enough for Sen. Bob Corker (R-Tenn.), as he did yesterday before the ad hit, to mildly rebuke Trump, without even mentioning him (“We all know what’s happening. It’s all about revving up the base, using fear to stimulate people to come out at the polls.”). They need to demand that the ad come down and implore their colleagues on the ballot to denounce it. If the colleagues refuse, Flake and Corker should pull endorsements from them.

The GOP has sunk to new lows, but likely not hit bottom. Unless soundly beaten in the midterms, Republicans will get even worse, as will the conduct they inspire.