ATLANTA — More than 30 million Americans have cast early ballots ahead of Tuesday’s midterm elections, eclipsing the 2014 early totals nationally and suggesting a high overall turnout for contests that could define the final two years of President Donald Trump’s term.

At least 28 states have surpassed their 2014 early votes.

The 30.6 million ballots includes data from 48 states, with several of those still collecting absentee ballots and welcoming in-person early voters. The total early vote in 2014 was 28.3 million in an election where more than 83 million Americans voted. That was a low turnout (about 36 percent) even by usual standards of a midterm, when there’s an expected drop off from presidential elections.

Forecasters aren’t predicting that overall turnout this year will hit 2016 levels (137.5 million; more than 60 percent of the electorate), but Democratic and Republican analysts, along with independent political scientists, say turnout could approach 50 percent, levels not seen for a midterm since the turbulent 1960s.