Well, trade protectionism is not a simple left right issue among average American citizens.
I know plenty of Americans who think the government should “protect” American industries and whom feel that other nations protect their industries against US products. This was a consistent theme of the Trump campaign.
Usually the political leadership and economists in both America’s political parties are not in favor of protectionist trade policies.
But republican presidents seem to be much more willing to actually go against their party’s orthodoxy around trade protectionism. GWBush did some trade protectionism with steel when he was president. President Obama did not. And now Trump does it again.
I don’t think this stuff helps the overall American economy. But unless it leads to a serious trade war that hurts the economy, my guess is this kind of stuff does not hurt Trump politically.