It was supposed to be a big, beautiful infrastructure bill. But President-elect Donald Trump’s pitch for a $1 trillion upgrade of the nation’s roads, bridges, tunnels and airports is already running into potholes as it meets reality in Washington. The overwhelming sticking point, as always, is how to pay for it. Key lawmakers say they’re in the dark on how Trump’s plan would work — with some conservatives simply hoping that his call for massive tax breaks will provide an economic jolt that makes the hard spending decisions easier. Hillary Clinton adviser Ron Klain denounced it Friday as a 'trap' that would provide 'a massive corporate welfare plan for contractors' without necessarily spurring any new infrastructure spending.