CNN is monitoring who is casting pre-election ballots in the 36 states that offer early voting, as well as how early voting numbers compare with four years ago, when pre-election voting reached historic levels during the Covid-19 pandemic.

This page, updated daily, draws on data from Catalist, election officials and Edison Research.

Democrats held a wide advantage over Republicans in early voting four years ago, but the gap could be narrower this time as top Republican officials urge supporters to embrace voting before Election Day on November 5.

Here are the pre-election voting breakdowns, by party preference, in key battleground states where registration information is available:

Another measure evident in the data so far is that older voters have made up a larger share of people casting ballots in battleground states, compared with this point in 2020.

The data also show early voting trends by racial and ethnic groups, offering clues about the makeup of the electorate. In some battleground states, a greater share of White voters have cast pre-election ballots than at this point in 2020.