Biden Facea Trouble With Rust Belt Workers
Democrat Joe Biden kicked off his 2020 presidential campaign in April.
The core of Biden's constituency are blue-collar voters.
There are signs of cracks in Biden's support.
More than a dozen current and former union leaders and workers who spoke to Reuters recently in Philadelphia.
They questioned Biden’s loyalty.
Pennsylvania has long been home to oil refineries.
Democrats aggressive environmental agenda may be boxing Biden out of an issue that seemingly plays into his brand of politics.