WASHINGTON — President Trump on Wednesday thanked a conspiracy theorist for saying Jews in Israel love the president “like he’s the King of Israel” and doubled down on his efforts to pit American Jews against one another, accusing Jewish voters of disloyalty if they voted for Democrats.

It was the second day in a row that Mr. Trump addressed Jews and loyalty, a theme evoking an anti-Semitic trope that Jews have a “dual loyalty” and are often more loyal to Israel than to their own countries.

“If you want to vote Democrat, you are being very disloyal to Jewish people and very disloyal to Israel,” Mr. Trump said Wednesday at the White House.

Speaking to reporters as he left the White House on his way to Louisville, Ky., to address a veterans group, Mr. Trump said his remarks were not anti-Semitic.