A couple of salient portions from the 538 article I linked:

In 2020, polls overestimated Biden’s margin over Trump by about 4 percentage points in competitive states. As of Oct. 30 at 11:30 a.m. Eastern, the margin between Vice President Kamala Harris and Trump in 538’s polling averages is smaller than 4 points in seven states: the familiar septet of Arizona, Georgia, Michigan, Nevada, North Carolina, Pennsylvania and Wisconsin. That means that, if the polling error from 2020 repeats itself, Trump would win all seven swing states and 312 Electoral College votes.

As of Oct. 30 at 11:30 a.m. Eastern, our forecast gives Trump a 52-in-100 chance to win the White House and Harris a near-identical 48-in-100 chance. The model arrives at that probability by calculating how many Electoral College votes each candidate would win given certain amounts of polling error in their favor, and then counting up how many times each candidate wins among these simulations. (More about that in our methodology.)