Donald Trump's call to renegotiate what he sees as unfavorable trade deals has struck a chord with many blue collar voters who traditionally vote for Democrats, and that could be hampering Hillary Clinton's own White House efforts,"Some of our members if not support [him] agree with some of Trump's statements," Joe Jacoby, union representative with Boilermakers Local 13 in Pennsauken, N.J., told the Post. "Because they feel like they're being hit hardest. Because their jobs are going away. Because it’s hard to find a good-paying job."That doesn't mean they'll cast their vote for the presumptive GOP nominee, Jacoby said, noting that he and other union leaders will be sticking with Clinton.Still, he said, Trump's message will have an impact because "Trade agreements are a big part of what we're arguing against, and he rings that bell."Trump's anti-free trade message goes against the traditional Republican stance, and he has openly said he wanted to court supporters of Clinton's Democratic opponent, Sen. Bernie Sanders.Though Clinton has the backing of the AFL-CIO and the United Auto Workers, at least two unions backed Sanders in the primaries, the International Longshore and Warehouse Union and the United Electrical, Radio and Machine Workers of America. Both say they don't intend to endorse anyone in the general election."The problem is that Clinton has been a free-trader her whole life, so we’re not going to endorse her," Peter Knowlton, president of the electrical-workers union, told the Post. "We will be running an anybody-but-Trump campaign. We have many members in swing states, and our major goal is for Trump not to get elected — not to make a pitch for Hillary."While they are not going pro-Trump, not backing Clinton could squelch the support of rank-and-file members who might either vote third party or just sit home on election day.AFL-CIO President Richard Trumka said Trump has "tapped into the legitimate anger and frustration that a lot of working-class people are feeling." But, he added, "Look at what he does, not what he says. He could have an effect on trade by bringing all the products he makes overseas back home and have Americans produce them. But he doesn’t do that."