With votes still being counted, turnout in the 2020 presidential election has hit a 50-year high, exceeding the record set by the 2008 presidential election of Barack Obama.

As of Sunday, the tallied votes accounted for 62 percent of the eligible voting-age population in the United States. That’s a 0.4 percentage point increase so far over the rate in 2008, when the nation elected its first Black president.

The number of votes also set records, although that’s less remarkable given the country’s growing population. So far 148 million votes have been tallied, with President-elect Joe Biden winning more than 75 million — the highest number for a presidential candidate. Incumbent Donald Trump received more than 70 million — the highest total for a losing candidate.

Election experts are debating the forces behind the rise in participation. Some pointed to the numbers as evidence of what happens when states expand the time and the ways voters can cast ballots, as many states did this year. Others noted the extraordinary high passions President Trump provoked — both for and against.

On Saturday, Biden was projected to have won the election with at least 279 electoral college votes. A candidate needs 270 of those votes to win.

The result: the highest turnout since 1968, according to data from the Associated Press and the United States Elections Project, which tracks turnout. Experts think the 2020 rate could hit heights not seen since the beginning of the 20th century, before all women were allowed to vote.

An Associated Press analysis shows that some of the biggest turnout increases to date occurred in states that expanded mail voting. In two states where it was expanded significantly, Montana and Vermont, turnout rose by more than 10 percentage points and more than 9 percentage points, respectively, over the previous presidential election, enough to put the states into the top 10 increases. Hawaii saw the biggest turnout increase, a more than 14 percentage point jump so far.

Texas, which did not expand mail voting but gave voters extra time to cast early ballots in person, saw more than 9 percentage point increase in turnout, moving from 50 percent to 59 percent of its citizen voting-age population going to the polls.

The highest turnout in the post-World War II era was in 1960, when 63.8 percent of eligible voters cast ballots, according to Michael McDonald, a political scientist at the University of Florida who runs the Elections Project. Turnout was higher before 1920, when some women won the right to vote, because the pool of people who could cast a ballot was smaller. That’s why McDonald and others think the 2020 election may surpass the 1908 high-water mark of 65.7 percent.

— Associated Press