JD Vance explained at a campaign stop in Pittsburgh that he believes Pennsylvania is trending red in part due to former President Trump’s tariffs proposal, warning battleground voters not to trust that Kamala Harris will revive U.S. manufacturing. JD Vance explained at a campaign stop in Pittsburgh that he believes Pennsylvania is trending red in part due to former President Trump’s tariffs proposal, warning battleground voters not to trust that Kamala Harris will revive U.S. manufacturing.