Roughly 16 million mail-in ballots ended up missing in the 2016 and 2018 elections, according to federal data.

Data from the U.S. Election Assistance Commission and the Election Administration and Voting Surveys for both the 2016 and 2018 elections show that 16.4 million ballots that were sent to registered voters by mail went missing, according to Breitbart News.

In the 2018 election, about 42.4 million ballots were mailed to registered voters. Of those mailed, more than 1 million were undeliverable, more than 430,000 were rejected, and nearly 10.5 million went missing.

“Putting the election in the hands of the United States Postal Service would be a catastrophe,” J. Christian Adams, president of the Public Interest Legal Foundation, said. “In 2018 and 2016, there were 16 million missing and misdirected ballots.”

“These represent 16 million opportunities for someone to cheat," Adams said. "Absentee ballot fraud is the most common, the most expensive to investigate, and can never be reversed after an election. The status quo was already bad for mail balloting. The proposed emergency fix is worse.”

The problem was especially bad in California, where 1.4 million mail-in ballots went missing in Los Angeles County alone during the 2018 election. In Orange County, the number was 374,000. The California counties of San Diego, Sacramento, Riverside, San Bernardino, Alameda, and Santa Clara combined for 1.6 million missing ballots.

Several states are debating whether to hold primary elections in person or to switch to an all mail-in ballot system to quell the spread of the coronavirus.

Earlier this month, the Public Interest Legal Foundation determined that there are thousands of ineligible voters, including many dead people, on the voter rolls in New Mexico who could receive mail-in ballots.

President Trump warned against mail-in voting earlier this week, saying, “Republicans should fight very hard when it comes to statewide mail-in voting. Democrats are clamoring for it. Tremendous potential for voter fraud, and for whatever reason, doesn’t work out well for Republicans.”