Dean Obeidallah, a former attorney, is the host of SiriusXM radio's daily program "The Dean Obeidallah Show" and a columnist for The Daily Beast. Follow him @DeanObeidallah. The opinions expressed in this commentary are his own. View more opinion articles on CNN. This piece has been updated to reflect the latest news.

(CNN) Election Day 2020 may still be a long way off -- 632 days to be exact -- but Donald Trump's re-election prospects are looking more challenging by the day. And I don't just mean because Trump has the highest disapproval rating (55.1%) of any modern-day president at this point in his presidency -- except for Ronald Reagan (55.5%) (Keep in mind Reagan was in the middle of a recession at the time in 1982.)

The potentially devastating challenge for Trump is the increasing number of strong women entering the Democratic field in 2020 to unseat him. While Trump defeated Hillary Clinton in 2016, this new group of women -- one of whom could ultimately win the nomination -- pose a significant threat to his re-election prospects, in part by drawing female voters to their side.

JUST WATCHED Sen. Gillibrand joins increasingly crowded 2020 Democratic field Replay More Videos ... MUST WATCH Sen. Gillibrand joins increasingly crowded 2020 Democratic field 03:36

Trump, who is prone to attack any person he views as a threat, will likely only hurt his own cause. With every negative tweet against them, he will remind Americans of his horrible record on gender issues -- including his seemingly blind defense of Alabama Senate Republican candidate Roy Moore and Supreme Court Justice Brett Kavanaugh, who were both accused of sexual assault (though they denied any wrongdoing). And who can forget his public mocking of Dr. Christine Blasey Ford, who testified under oath that Kavanaugh had assaulted her?

We have already seen the impact of Trump's conduct on female voters in the 2018 election, when Democrats attracted 59% of the female vote -- causing a record gender gap for a midterm election. And unless Trump and the GOP make drastic changes in the near future, 2020 could be even worse.

But it's not just about what Trump has said or done. It's also about what these female candidates are saying and doing.