Turbulence shakes Democrats going into final debate of 2019

A deepening sense of volatility is settling over the Democratic Party's presidential primary election on the eve of the sixth and final debate of 2019. The seven candidates who remain are being forced to grapple with unprecedented distraction from Washington. There also are questions about their core principles and new signs that their party's energized factions are turning against each other. Lest there be any doubt about the level of turbulence in the race, it's unclear whether Thursday's debate will happen at all given an unsettled labor union dispute that might force participants to cross a picket line.