Via Politico:
Democrats pulled off a mostly successful national party convention this week under extraordinarily challenging circumstances.
But Joe Biden still shouldn’t expect much of a polling bounce.
Biden has already consistently led President Donald Trump in national and battleground state surveys in what has been a remarkably stable race since he emerged as the Democratic frontrunner in March. That stability has also matched the steadiness in Trump’s approval ratings, which have remained in a narrow band throughout his tumultuous presidency.