When Mike Sylvester entered a career training center earlier this year in southwestern Pennsylvania, he found more than one hundred federally funded courses covering everything from computer programming to nursing. He settled instead on something familiar: a coal mining course.”I think there is a coal comeback,” said the 33-year-old son of a miner.Despite broad consensus about coal’s bleak future, a years-long effort to diversify the economy of this hard-hit region away from mining is stumbling, with Obama-era jobs retraining classes undersubscribed and future programs at risk under President Donald Trump’s proposed 2018 budget. Trump has promised to revive coal by rolling back environmental regulations and moved to repeal Obama-era curbs on carbon emissions from power plants.“I have a lot of faith in President Trump,” Sylvester said.But hundreds of coal-fired plants have closed in recent years, and cheap natural gas continues to erode domestic demand. The Appalachian region has lost about 33,500 mining jobs since 2011, according to the Appalachian Regional Commission.Coal miners are resisting retraining without ready jobs from new industries, but new companies are unlikely to move here without a trained workforce. The stalled diversification push leaves some of the nation’s poorest areas with no clear path to prosperity.