Trump's visit to Las Vegas was part of a more aggressive push by the White House to shift attention toward the success of progressive candidates as voters remain unhappy with the president's handling of the economy and the Iran war.
His meandering speech to a crowd of loyalists at Red Rock Casino came a day after progressive candidates scored key victories in Michigan's Democratic primaries on Tuesday.
Trump spent time focusing on tax provisions in last year's Republican spending package, including measures eliminating taxes on tips, overtime pay and Social Security income for many Americans.
But the victories by progressive Democrats in Michigan and other Democratic primaries were a dominant theme for Trump.
Democratic socialists, he said, represented the creeping threat of communism and threatened to destroy the American way of life.
"I think it's the greatest threat," he said.
Neither of the two winning Democratic candidates in Michigan identify as Democratic socialists, although some progressive candidates who emerged victorious in earlier primaries do.
Trump used the event to attack Abdul El-Sayed, who won the Democratic Senate primary in Michigan and will face Trump-backed Republican Mike Rogers in the November election.
"He doesn't love Israel. He doesn't love Jewish people. He hates them. He hates them with a passion that burns in his heart, and there's not a fricking thing he can do about it."
El-Sayed has condemned anti-Semitism and said criticism of Israel's assault on Gaza and its occupation of Palestinian territories should not be equated with anti-Semitism.
Beset with sagging poll ratings, Trump complained he is not getting proper credit for his policies.
"I don't get any credit for anything," he said.
Trump appeared with Republican congressional candidate Marty O'Donnell in the Las Vegas-area district represented by Democratic Representative Susie Lee, one of the closely watched House battlegrounds.
Trump credited Las Vegas' service industry workers, a critical voting bloc in Nevada, with inspiring the legislation's temporary "no tax on tips" provision.
Democrats unanimously opposed the legislation, which they said was a giveaway to wealthy Americans at the expense of social safety net programs such as Medicaid and food assistance.
