Over half a million absentee ballots were rejected for the 2020 presidential primaries — that's 200,000 more than what was rejected in 2016

• An NPR analysis reported that over 550,000 mail-in ballots have been rejected in the 2020 presidential primaries.
• The NPR analysis noted that this is far beyond the 318,728 ballots rejected in the 2016 general election.
• Ballots can be rejected for mistakes like missing signatures, but a number of ballots are not arriving on time in the first place and thereby being rejected.
• Ahead of a presidential election predicted with more mail-in-ballots because of the coronavirus pandemic, rejected ballots are among a number of problems that could jeopardize the November election.

Over 550,000 mail-in ballots have been rejected in the 2020 presidential primary election, a new analysis by NPR reported.

NPR's cumulative count for rejected mail-in ballots found that 558,032 mail-in ballots were rejected in states for the 2020 presidential primaries, an alarming leap from the 318,728 rejected in the 2016 general election. NPR noted that the number is "almost certainly an underestimate" since not all states publicly released the number of rejected ballots.

Thousands of mail-in ballots are rejected for mistakes including missing required signatures, being improperly sealed, or not being placed in a privacy envelope, Business Insider's Grace Panetta previously reported. At the same time, delays in mail delivery have provoked fear that ballots will fail to arrive at all to be counted in time for the election.

These rejected ballots could prove to be critical for the election – particularly for battleground states. More than 23,000 absentee ballots were rejected in Wisconsin's presidential primary in April – this is a state in which Trump won by almost 23,000 votes, according to NPR.

The upcoming presidential election, where a large number of voters are expected to mail in their ballots due to the coronavirus pandemic faces a myriad of problems: Confusion over where to vote, having to wait in long lines, and not receiving ballots on time, are among the many concerns that loom over ahead of the presidential election. The strikingly high number of mail-in ballots that were rejected in the primaries amplifies these concerns.

• Read more:
• Voting 2020: See the deadlines to apply for and submit your mail-in ballot in every US state
• How to vote by mail in your state in the November presidential election
• 'Is this a joke?' North Carolina voters are being mailed absentee ballot request forms with Trump's face on them
• 'They're not needed, sir': Postmaster General Louis DeJoy says USPS won't replace removed mail-sorting machines