Would Trump have a decisive victory without mail-in ballots?

Bill (Yes)

President Trump would have won a decisive victory without mail-in ballots. Trump was suspicious of mail-in ballots and discouraged their use. So, naturally, most of the mail-in ballots favor Biden, since Democrats largely requested them. The use of mail-in votes raises the specter of voter fraud.

A sampling of election fraud examples has been compiled by the Heritage Foundation and includes over 1,000 proven instances of voter fraud. Election fraud cases often involve absentee (mail-in) ballots. Recent examples include a Hudson County, New Jersey postal worker who was arrested for discarding mail. A US Department of Justice investigation uncovered more than 1,800 pieces of mail, including 99 absentee ballots, in a dumpster. And finally, a video has captured mail (including absentee ballots) being stolen in Escondido, CA. Simply put, mail-in ballots are fraught with tampering potential. 

In addition, human error (whether intentional or not) can also nullify election results. USA Today reported a month ago 'that close to 100,000 New York City voters received mail-in ballots with incorrect names and addresses.' Out-of-date local voter rolls also increase the potential for fraud. There are simply no uniform processes and technology in place to ensure that the current address of all registered voters is kept current. To make matters worse, it's a problem for local municipalities who may not have the resources or technology budgets to invest in tackling this data challenge. Prior to counting mail-in ballots on election night, President Trump was leading in all the battleground states. The election outcome is currently in dispute as the validity of those mail-in ballots is being challenged.

Andrew (No)

While President Trump would likely have won the 2020 election had mail-in votes not been counted, his win would not have been decisive. On election day, the president had small leads in states like Georgia and Pennsylvania, which trended toward his opponent as mail-in votes were counted. In this scenario, the president would have likely won Georgia, North Carolina, Pennsylvania, and possibly Nevada, Michigan, and Wisconsin as well. These would have been small victories, by no more than a couple of percentage points each. This might look like a strong victory because of our antiquated electoral system. Still, the reality is that only a very slim percentage of people would have preferred the president in several key states. Though President Trump may have won the election, it's also possible he might have lost the popular vote again.

The problem with disqualifying mail-in ballots is that people were assured they could use this pandemic-safe option and chose to do so. It's impossible to say that President Trump would have had a decisive win without mail-in ballots because doing so would be to blatantly ignore a portion of the eligible votes by moving the goalposts at the last minute. It's clear that not counting mail-in ballots would have only lowered voter turnout. The final percentages would not have been different enough for President Trump to have had a definitive victory. To say that President Trump would have had a decisive victory is similar to saying that he would have won as long as only the votes cast for him were counted.