Biden says democracy at stake as Republicans eye 'red wave'

With all 435 seats in the House of Representatives up for grabs alongside a third of the 100-member Senate, Democrats were putting a brave face on their prospects- but the latest polls have put them on the defensive. US midterm elections are typically seen as a referendum on the president in power, whose party tends to lose seats in Congress, particularly if- as with Biden- his approval rating is under 50%.