Trump enters election year with big wins - and bigger political headwinds

WASHINGTON, Dec 20 (Reuters) - President Donald Trump stormed back into office with a shock-and-awe policy blitz that expanded presidential power and reshaped America's relations with the world. But it has come at a steep cost: as he enters the New Year and midterm elections loom, his once unshakeable hold on Republicans is slipping, say historians and analysts. Back in January, as Trump