Senate candidates endorsed by Donald Trump have struggled of late, from Sean Parnell’s withdrawal in Pennsylvania while denying allegations of domestic abuse to the former NFL star Herschel Walker angering party leaders with his run in Georgia.

But to one candidate for the Republican nomination in Missouri, Congressman Billy Long, the former president’s endorsement still carries the ultimate weight.

“If he endorses in this race,” the 66-year-old told Politico, “I don’t care who he endorses, it’s over … And that’s what I’m trying to impress upon him is that, you know, ‘You need to get involved in this race and put an end to it.’”

Long said he would tell the former president: “You’re looking at the guy that was with you from day one.’ Never ever left. I mean, look at this tie.”

The former auctioneer duly showed off his neckwear, a gold striped number signed, apparently in his signature Sharpie marker, by Trump himself.

Long said Trump signed the $37 tie in Nevada in 2016, when Long spoke on his behalf. Long has had – and auctioned off – other ties signed by the president, including a striking example featuring flags and caricatures which Long wore to the State of the Union in 2019.

Trump’s own ties played a prominent role in the 2016 election and its aftermath.

In 2015, Macy’s made news when it dropped Trump’s menswear line – many headlines said the retail giant was “cutting ties” – over his racist remarks about Mexicans at his campaign launch.

In 2019, the former New Jersey governor and Trump ally Chris Christie revealed that Trump advised him to wear longer ties in order to look slimmer.

Politico described Long as “built like a lineman” and said he spoke with a “thick ‘Missoura’ twang”. In Missoura’, whose other sitting senator is the Trump-supporting controversialist Josh Hawley, a large field is jostling to replace the retiring Roy Blunt.

One candidate, Mark McCloskey, rose to fame in 2020 when he and his wife pointed guns at protesters for racial justice near their home in St Louis. Both pleaded guilty to misdemeanours. Another, Eric Greitens, resigned as governor in 2018, amid scandals over sex and campaign finance. Criminal charges were dropped.

Speaking to Politico, Long called Greitens “Chuck Schumer’s candidate”, a reference to the Democratic leader who will defend control of the Senate next year, hoping to face weak or controversial Republicans in key states.

A spokesperson for Greitens told Politico: “Billy Long is a much better comedian than he is a Senate candidate.”

Observers including Blunt said Long, who also has a habit of handing out fake money with Trump’s face on it, had a chance of winning Trump’s endorsement.

But though Long voted to object to electoral college results in 2020 he has also recognised Joe Biden as president, thereby failing a key test in a party in Trump’s grip.

Long told Politico he would not follow his leader in the House, Kevin McCarthy, to Florida to worship the party’s golden idol.

“I have people say: ‘Call him, call him every day. Go sit at Mar-a-Lago and tell him you’re not leaving till he endorses,’” Long said. “I’m smart enough to know that’s not going to win favour with Donald Trump.”

Others might say that it would.