Democratic voters' opinions of Bernie Sanders improved but declined for Joe Biden and Elizabeth Warren in Iowa run-up

On January 22, Insider polled 426 likely Democratic voters whether their opinions of the 2020 candidates they knew of had improved or declined at all in January. Sanders' performance in both national, Iowa, and New Hampshire polls has dramatically increased over a relatively short period of time. More Democratic voters said their view of Biden changed for the worse, with 35% saying it declined in January and just 18% saying it improved, a net shift of 17 percentage points for the worse.Sanders appears to be peaking at exactly the right time in the week before the Iowa caucus and New Hampshire primary.