Trump's 2020 campaign should be alarmed by this polling expert's new numbers
President Donald Trump (AFP / NICHOLAS KAMM)

Polling expert Kyle Kondik has been analyzing some recent numbers about President Donald Trump's approval rating and has discovered a trend that should be alarming to the president's 2020 campaign.

Writing at the Sabato's Crystal Ball website, Kondik argues that one of Trump's big keys to victory in 2016 was the way he overwhelmingly won voters who disliked both him and Hillary Clinton.

Fast forward three years, however, and Trump is now actually running behind his overall job approval rating -- meaning that even voters who say they like the job he's doing are reluctant to vote for him again in 2020.

"However, in some early ballot tests, there is some indication that Trump is not only failing to pick up support from people who don’t like him, but in some instances he does not appear to be winning every poll respondent who approves of his job performance," he writes. "The Fox News poll released last week found that Trump’s approval rating among registered voters was 46%, but he only attracted between 39%-42% of the vote in matchups against the top-polling Democratic presidential contenders."

Given how Trump's disapproval rating has consistently been over 50 percent for the majority of his presidency, Kondik explains, he has a very narrow path when it comes to winning again in 2020.

"The differences here are slight, but this is something worth monitoring because Trump’s path to victory probably entails him either improving his approval rating so that it’s in the mid-to-high 40s as opposed to the mid-to-low 40s, or running ahead of his approval by capturing a small but significant number of voters who don’t approve of him," he writes. "But if Trump is actually losing a small number of voters who approve of his job performance, he may have a very hard time cobbling together another Electoral College majority."