Voters pass a sign outside a polling site in Warwick, R.I., Monday, Nov. 7, 2022, after casting their ballots on the last day of early voting before the midterm election.

Video. America votes: What might a Republican victory mean for Europe?

There's concern that success for Trump supporters in Tuesday's vote may jeopardise aid for Ukraine, damage transatlantic ties, and galvanise Europe's far-right.