The unconventional presidency of Donald J. Trump is about to come up against a longstanding trend in American politics: The President’s party usually loses seats in mid-term elections, and the rest of his term is never the same again. A Congressional district in Ohio that has been in Republican hands for almost a century, and where Mr Trump won big in 2016, nearly went to a Democrat in last week’s by-election. This has fanned Democratic hopes for a “blue wave” in the Nov 6 election that will decide all 435 seats in the House of Representatives and 35 of the 100 seats in the Senate. The Democrats need to increase their tally by about two dozen seats to win back the House and by two seats to retake a majority in the Senate.

The verdict from Ohio and various Congressional primaries under way reveals that Mr Trump’s influence with his working-class base endures. But he seems to have lost the faith of the suburban voters, including white women, who supported him in 2016. Alarmingly for him, the rebounding economy, with improving corporate bottom lines and historically low unemployment rates, has made no difference to his job approval ratings. Never higher than 45 per cent since his inauguration, they continue to stagnate. This is a signal perhaps that, even if voters are persuaded that the new world order that Mr Trump is attempting to fashion will leave Americans better off, his leadership style is wanting.