THE 2018 midterm elections are the first national vote since Mr Trump claimed the White House in his shock victory two years ago - and many see them as a referendum on his administration.

Casting his vote in Delaware, former Vice President Joe Biden predicted that Trump would question the legitimacy of the vote if the result goes against him.

But veteran Democrat strategist James Carville said early hopes of a "blue wave" election will likely be dashed, after early results pointed only to modest gains.