Keith Caviness does not know who he wants to succeed Donald Trump in the White House in four years’ time. But the life-long Iowa Republican has a requirement for whoever comes next.

“The one thing we don’t want is somebody that is less than Trump. We have got to be as good as or better,” Caviness said at the Republican party of Iowa’s annual Lincoln Dinner last week, adding: “That is a tall order, as far as I am concerned. How long have we been waiting for Donald Trump to show up?”

Trump may only be six months into his second term in office — and enjoying an approval rating as high as 90 per cent among Republican voters — but some parts of his party are already discussing who might succeed him. One potential candidate tentatively laid out his stall at the recent Iowa fundraising dinner, and others are heading to the state in the coming weeks.