Democrats were quick to back working-class United Auto Workers in their strike against General Motors, delivering doughnuts and holding picket signs outside factories to show solidarity. It’s a union they long have aligned with politically.

There were no doughnuts from Republicans.

Led by President Donald Trump, GOP officials have largely avoided taking sides in the strike that threatens to upend the economy in Michigan, an election battleground, a year before the 2020 vote. Both here and nationally, most Republicans said little about the substance of the dispute beyond hope for a speedy resolution.

The muted response reflects the tricky politics of labor for Republicans.

Trump has made inroads with members of some unions, due partly to promises to get tough on trade and keep manufacturing jobs in the United States. The message pulled key voters away from their Democratic union bosses, who Trump argues are corrupt.

But a strike prompted in part over GM’s plan to close American plants highlights Trump’s unfulfilled promises on manufacturing and gives Democrats a chance to play up their union credentials.

Democratic presidential candidate Elizabeth Warren planned to show up on the picket line in Michigan on Sunday, with rival Bernie Sanders expected this coming week. Nearly all the candidates have tweeted support for the workers.

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