ABC television star Roseanne Barr is in full retreat. Today, she tweeted, “I apologize to Valerie Jarrett and to all Americans. I am truly sorry for making a bad joke about her politics and her looks. I should have known better. Forgive me-my joke was in bad taste.”

A mere matter of taste? On Tuesday, she had tweeted, “Muslim brotherhood & planet of the apes had a baby=vj.” Jarrett was a top former aide to president Obama.

America is awash in a sea of vilification, much of it being disseminated from the White House, where Donald Trump offers what amount to daily lessons in the objurgatory arts. Unlike Roseanne, who is now threatening a self-imposed Twitter exile, it seems to work for Trump whose natural habitat is the netherworld of calumny and conspiracy theories. Only last week he was droning on about “Spygate,” the brouhaha surrounding the Cambridge professor Stefan Halper who contacted a few officials in the Trump campaign, that was supposed to represent a diabolical attempt on the part of the FBI to infiltrate his team and ensure Hillary Clinton’s election. It was supposed to be worse than Watergate.

Now that Spygate as Trump labeled it, has petered out, Trump is moving on to a fresh slander. Special Counsel Robert Mueller and “13 Angry Democrats,” we are told, hope to rig the midterm elections against Trump and the GOP. Trump doesn’t say exactly how they would accomplish this feat, but never mind. When it comes to assailing Muller and his team, Trump is proving effective at keeping congressional Republicans and his base from defecting.

Trump’s real concern isn’t about the probity of the Mueller investigation. No one knows better than Trump, who continues to refuse to release his tax returns, the extent of the financial shenanigans that he engaged in before becoming president. His only fear is that Mueller will reach the end of his investigation unmolested.

Even as he brays about Mueller, Trump is intent on returning to his favorite territory, which is the campaign trail. NBC reports that Republicans are devising a two-front campaign. The first consists of forcing Senate Democrats to remain in Washington to vote on a welter of judicial nominees. This is supposed to minimize the time they can spend on the hustings. The second will send Trump himself around the country to whip up support for Republican candidates. The theory is that Trump should go all-in since his political fates depends upon retention of the House and Senate.

But will it work? The problem for the GOP is that Trump is so incendiary that his presence may prompt more Democrats than Republicans to vote in the midterms. So far, Trump’s record is poor, whether in the Alabama Senate election or the Pennsylvania congressional one. The Democrats, who are capitalizing on anger about Trump’s outlandish behavior and policies, including stripping children from their parents at the border, may be well-positioned to make substantial gains in November. As the elections approach, it will be intriguing to keep a score sheet of the serial conspiracy theories that Trump invents to dodge responsibility if a fiasco looms.