Donald Trump was back to his old tricks. Speaking before thousands of fans in western Iowa last week, the president conjured up a nickname for his latest target — a Democrat named Cindy Axne who is hoping to become the first woman to represent Iowa in the House of Representatives.

“Cindy Tax Me. It’s a very good name?.?.?.?I guess it’s actually Axne, but we call her Tax Me,” Mr Trump roared, sending ripples of laughter across the packed arena in the city of Council Bluffs. “That was so easy!”

Mr Trump was revelling in the sort of gamesmanship that helped him win the White House. But this year he has a very different goal. The rally was just one stop on a hectic tour designed to help Republicans defend their increasingly at-risk majority in the House and keep control of the Senate.