One of the GOP founders of the anti-Trump group The Lincoln Project said Wednesday that polls undercount the level of support that exists for President TrumpDonald John TrumpThe Memo: GOP seeks to detoxify Trump at conventionHarris honors Women’s Equality Day in op-ed, calls for voting reformTrump breaks with precedent on second night of conventionMORE.

It is historically difficult to defeat an incumbent president, No. 1, Steve Schmidt, a former adviser to Sen. John McCainJohn Sidney McCainThe Hill’s 12:30 Report: Sights and sounds from GOP convention night 1Red meat for the right wingers will be the main course at RNCHow Trump can win reelection: Focus on Democrats, not himselfMORE (R-Ariz.), told Andrea Mitchell on MSNBC. I suspect there is at least a point or two of undercount for Trump voters.

Polls show Democratic presidential nominee Joe BidenJoe BidenHarris honors Women’s Equality Day in op-ed, calls for voting reformTrump breaks with precedent on second night of conventionMelania Trump casts president as champion for American familiesMORE with a healthy lead in national polls. Biden has smaller leads in most of the six core battleground states, although recent surveys have found the race is tightening.

The presidents campaign has routinely dismissed polls showing Trump is behind, pointing to 2016, when most election analysts didnt give him any chance of winning. Trump edged out Democrat Hillary ClintonHillary Diane Rodham ClintonKanye West makes it on the ballot in MinnesotaHillicon Valley: Lawmakers introduce resolution condemning QAnon | US Cyber Command leader vows to ‘defend forward’ in protecting nation from cyberattacksTrump revives 2016 playbook for Biden battleMORE in most of the battleground states and eked out victories in Pennsylvania, Wisconsin and Michigan, which had not gone for the GOP candidate in decades.

Trumps campaign has attributed the bad polling in 2020 to the so-called shy Trump voter phenomenon. They say there are scores of voters who will not admit to pollsters they support the president, believing it could be socially problematic for them to do so.

The polling outlet Trafalgar Group, which was the only pollster to show Trump ahead in Michigan on Election Day in 2016, seeks to account for this so-called social desirability effect in its polls. The lead pollster there has told The Hill there are more silent Trump voters in 2020 than there were in 2016.

Trafalgars polls have shown a tighter race than what other pollsters have found. One of their recent surveys found Trump and Biden tied in Minnesota, a state Clinton won in 2016 that the Trump campaign insists is up for grabs in 2020.