Trump threatened 'very serious consequences' if Elon Musk finances challengers to Republicans who support his legislative priorities.

The broken alliance between the President and world's richest man could threaten Musk's lucrative pending -- and future -- federal subsidies.

WASHINGTON (Reuters) -Donald Trump threatened on Thursday to cut off government contracts to Elon Musk's companies and the world's richest man suggested the U.S. president should…