(CNN) President Donald Trump was able to win in 2016 because he was seen as the lesser of two evils. His victory came from the voters who didn't like either candidate. A large part of that came from the belief that voters saw neither one as honest.
Trump's matchup with former Vice President Joe Biden isn't falling into that same paradigm.
In what marks perhaps the biggest difference since the presidential election four years ago, Trump is clearly losing the debate over which candidate is seen as more honest and trustworthy this time around.
Take a look at the latest Pew Research Center poll, released on Tuesday. Voters were asked whether the word "honest" described Biden and Trump well.
Biden won the battle. A near majority (48%) said "honest" characterized him very or somewhat well. It was just 36% for Trump. This 12-point advantage was nearly equal to the 10-point lead Biden had over Trump overall in the poll.
View 2020 presidential election polling
It's not just the Pew poll, either. In a Quinnipiac University poll in June, 44% said Biden was honest, compared with 35% who said it for Trump. The 9-point edge for Biden translated to an 8-point lead in the ballot test. The same can be said of an ABC/Washington Post poll late in May. Biden was up 12 points on honesty and trustworthiness and ahead by 10 points in the horse race.
In other words, there's a strong correlation between seeing a candidate as honest and whether a person is going to vote for him or her.
Last time, Trump won the honesty matchup in the most important states. More voters said he was honest and trustworthy in the Michigan, Pennsylvania and Wisconsin exit polls. Nationally, Hillary Clinton's 3-point margin over Trump on the honest and trustworthy question was nearly identical to her 2-point win in the popular vote.
Interestingly, it's not as if Trump is viewed as any less honest today than four years ago. Only 33% said he was honest and trustworthy in the 2016 exit poll. Today, it's usually around 35%, depending on the poll.
The difference is that Biden is seen as far more honest than Clinton was. While 36% of voters said Clinton was honest and trustworthy in the exit poll, around 45% to 50% said the same about Biden in any individual poll right now.
It's also important to make a comparison with where Clinton and Trump were at this point in the campaign.
The numbers at this point in 2016 were pretty equal to how they ended up in November. A third of voters (33%) said Clinton was honest and trustworthy in a June 2016 CBS New poll. About the same slice of the pie (32%) believed Trump was honest and trustworthy.
This means that despite all of the ads for and against Clinton and Trump, the honesty numbers didn't budge from June to November.
Therefore, when former FBI Director James Comey's letter reopening the investigation into Clinton's emails was released in the late stages of the 2016 campaign, it wasn't like it gave voters an epiphany. The underlying belief many voters had that Clinton wasn't honest had been sewn long before that point. The letter simply brought the idea that Clinton wasn't honest or trustworthy back to the forefront.
Looking to the rest of the 2020 campaign, Trump is likely to try to shift Biden's numbers more toward Clinton's. He has recently called Biden "Corrupt Joe" on Twitter. It's not clear at all Trump's efforts are going to work.
The one bet I would make is that it'll be difficult for Trump to win if voters see Biden as more trustworthy by a double-digit margin. The candidate seen as more honest usually wins. Bill Clinton in 1996 was the last candidate to pull off a win when voters clearly believed the other major-party candidate was more honest.
That's not a particularly good track record if you're Trump.