White Sulphur Springs, West Virginia (CNN) The 2018 midterm elections were expected to be the backdrop to President Donald Trump's remarks here on Thursday. Instead, they became the main event.

Minutes after taking the stage, Trump went after the state's Democratic senator, Joe Manchin, for voting against the GOP tax reform bill and urged voters to vote him out of office.

"I thought he would be helpful because he talks," Trump said of Manchin. "But he votes against everything. And he voted against our tax cuts."

Next, he blamed Democrats -- once again name-checking Manchin -- for what he deemed to be the United States' "very weak" immigration laws, slamming family-based immigration and calling for the end of "catch and release" policies. He even revived his unsubstantiated claim that "millions and millions" of people voted illegally in the 2016 election, in which he won the presidency but lost the popular vote.

"In many places the same person in California votes many times," Trump said Thursday. "They always like to say, 'Oh that's a conspiracy theory.' It's not a conspiracy theory. Millions and millions of people, and it's very hard because the state guards their records."

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