Trickle or tsunami? Democrats eye gains in US midterm elections

Will it be a trickle, a wave, or a tsunami? It's Election Day in the United States, with Democrats hoping to take back one or both houses of Congress. We track the turnout, gauge the mood and raise the curtain ahead of midterm results that are sure to shape the last two years of Donald Trump's second and final term. Will a US president who’s already broken norms with his maximum use of executive powers be affected by the results a little, a lot, or not at all?