Campaigning in April ahead of the US midterms, Donald Trump earned rapturous applause from a crowd in Michigan’s manufacturing heartland as he said he was single-handedly bringing the auto sector back to the state.

The president’s sunny assessment of his policies suffered a serious blow on Monday, as General Motors announced it was shutting two of its Michigan plants, along with closures in Ohio, Maryland and overseas.

The car giant’s decision triggered disapproving comments from the president. Michigan and Ohio are politically pivotal states that will be fiercely contested in the 2020 election. The president’s pledges to revive car manufacturing have proven popular in the midwest. The auto workers of south-east Michigan, where he held the April rally, helped deliver the state to the Trump campaign by the narrowest of margins.