Democrats worried about polls undercounting Donald Trump’s support

Prospects of ex-president's victory could be higher as some Harris supporters unnerved by small lead in swing states

Democrats are increasingly worried that pollsters are undercounting Donald Trump's voter support, rating his prospects of winning November's presidential election as much higher than headline opinion polling figures suggest.

While most national surveys show consistent, though moderate, leads for Kamala Harris, the Democratic nominee, some supporters are unnerved by the small margin of her advantage in three northern battlegrounds - Pennsylvania, Michigan and Wisconsin - which are deemed must-wins in her quest for the White House.