Donald Trump returned to the campaign trail on Wednesday, imploring North Carolina voters to “pretend I’m on the ticket” and “crush the communists” in the November elections at a rally in support of the Republican Senate nominee Michael Whatley.

Despite Trump’s deep unpopularity, Republicans hope to once again turn the president’s loyal following into a political force as the party confronts an unforgiving midterm landscape.

“I’m not bragging, but when I’m on the ticket Republicans have always done really well,” Trump told supporters. “I just want you to go out and pretend I’m on the ticket, because essentially I am.”

The rally, Trump’s first campaign event since the Republican party’s unusual midterm convention in Dallas last week where he debuted a similar campaign message, was aimed at energizing Republican voters behind Whatley, a former Republican National Committee chair who is running in a crucial battleground race against the Democratic former governor, Roy Cooper.

With the Republican senator Thom Tillis retiring, Democrats see a rare opportunity to flip a seat in a state that has repeatedly dashed the party’s hopes in recent elections, but which could decide the balance of power in the Senate this November. To win control of the Senate, Democrats must prevail in at least four Republican-held seats.

In Gastonia, Trump sought to cast the Senate contest as a referendum on Cooper’s governorship, saying the election was about “safety” and “bad management”.

From the stage, he invoked the murder of Iryna Zarutska, a 23-year-old Ukrainian refugee fatally stabbed on a Charlotte light rail train last year. Describing the attack in gruesome detail, he falsely claimed that the man arrested and charged with her killing, Decarlos Brown Jr, had been released from prison by Cooper.

He then showed dozens of mugshots on a video screen, explicitly comparing his attack on Cooper to the notorious “Willie Horton” attack ad used by George HW Bush’s 1988 presidential campaign against Michael Dukakis in a racially charged appeal to cast the Democratic nominee as weak on crime.

“Years ago in Massachusetts, there was a governor named Dukakis, Michael Dukakis, you remember, who had a very substantial lead for president,” Trump said. “He was going to win easily, but he allowed a man named Willie Horton out of jail. Willie Horton was a bad guy, really bad guy. Same thing as this. Same exact thing.”

Trump said Whatley was the “candidate of law and order” who preferred criminals be “executed, arrested or deported”.

Trump’s appearance underscored Republicans’ challenge in North Carolina, a place where Democrats have not won a Senate race since 2008 but where polls have consistently shown Cooper ahead of Whatley.

Nodding to Cooper’s edge, Trump claimed there was a misconception about the former governor’s politics.

“He tries to pretend he’s a moderate,” Trump said of Cooper. “He’s not.”

Trump lavished praise on Whatley, his hand-picked choice for Senate calling him a “ball-breaker” and “one of the greatest men I ever worked with in government”.

“I had my choice of the whole country,” Trump said. “I chose Michael Whatley.”

Whatley enthusiastically returned the embrace, praising Trump as the “greatest president of our lifetime”.

Ahead of the rally, local Democrats held a news conference to denounce Whatley for supporting Trump’s agenda.

“Why would Whatley back a war that is driving up prices for North Carolina families at a time when it’s already too hard for us to get by?” state senator Woodson Bradley said. “Let’s not find that out, North Carolina. He’s already shown us everything we need to know.”

By tying himself to the president, Whatley is hoping Trump’s command of the party’s base can translate into broader support in a state where independent voters make up a large share of the electorate and where concerns about prices, the economy and the administration’s handling of the war in Iran have complicated the political landscape.

Yet in a reminder of the significant economic headwinds Trump is facing, he spent time attacking the Federal Reserve, which on Wednesday raised its benchmark interest rate by a quarter-point, its first increase since 2023. The Fed said persistent inflation warranted the move.

Speaking to reporters on the tarmac before the rally, Trump called the central bank “very hostile” to him and said its officials were a “bunch of politicians”.

“They’re doing the wrong thing,” he said, repeating several times that interest rates were “too high”.

Robert Mackey contributed reporting