More than a third of Americans believe President Joe Biden’s victory was illegitimate, according to a new poll conducted almost a year since rioters breached the U.S. Capitol as Congress worked to certify the 2020 election. A new University of Massachusetts Amherst poll released Tuesday highlights how partisanship has hardened in the year since the deadly Jan. 6 attack and the stark breakdown on how Democrats and Republicans view that day and the results of last November’s presidential race. Fifty-eight percent of respondents surveyed across the country believe Biden’s victory was legitimate, while 33% contend it was illegitimate – numbers...