CNN is tracking who is casting their ballots before the election in the 36 states that offer early voting and how the number of early voting compares to four years ago when voting before the election during the Covid-19 pandemic reached a historic level.

Updated daily, this page is based on data from Catalist, election officials and Edison Research.

Four years ago, Democrats had a big advantage over Republicans in early voting, but this time the gap may be narrower as top Republican officials urge their supporters to vote before Election Day on Nov. 5.

Voters are registered by party in four of the seven contested presidential elections, and in each of those four, Democrats have cast a smaller share of the primary vote this year than they did at this point in 2020. Registration data by party is not available for the battleground states of Georgia, Michigan and Wisconsin.

The overall decline in interest in early voting so far should come as no surprise.

The 2020 election saw historic levels of primary voting during the COVID-19 pandemic. Some voters had concerns about voting in person because Centers of Disease Control and Prevention guidelines recommend social distancing. Four years later, as the country emerges from the pandemic, more voters may be heading back to the polls to vote in person either before or on Election Day.

Another measure apparent from the data so far is that older voters make up a larger share of people casting ballots in battleground states compared to this point in 2020.

The data also shows early voting trends by racial and ethnic groups and provides clues about the composition of the electorate. In some battleground states, a larger share of white voters voted before the election than at this point in 2020.