If an amalgam of McCarthyism and the notorious Willie Horton ad suits your taste, then you want to get hold of a mailer sent to Long Island voters on behalf of the Republican candidate for Nassau County executive. As odious campaign material goes, this one is hard to beat. Yet the candidate, Jack Martins, says he firmly stands by it.

The mailer shows three shirtless Latino men, covered in tattoos and representing MS-13, the vicious gang begun by Central American immigrants in Los Angeles that now menaces Long Island. “Meet Your New Neighbors!” a headline above them says, adding this about Mr. Martins’s Democratic opponent: “Laura Curran will roll out the welcome mat for violent gangs like MS-13!” Ms. Curran, the text says, is “MS-13’s choice for county executive.”

Image A campaign mailer sent by Jack Martins. Credit... Newsday

That was the Willie Horton part of the message — a blatant race-based appeal to fear. You may recall the Horton commercial, which the elder George Bush ran in his 1988 presidential campaign. It showed a black man who had raped a white woman and assaulted her husband while free on a Massachusetts prison-furlough program that was supported by Michael Dukakis, the Democratic candidate. As a vote magnet, it worked for Mr. Bush. Mr. Martins, a former state senator, clearly hopes it does the same for him in Tuesday’s election.