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.

(CNN) Hillary Clinton's nearly 66 million votes in the 2016 election weren't enough to defeat Donald Trump. But just over 0.0001% of that could end Trump's presidency. That's the reality of what Trump faces now that he has been formally impeached by the House of Representatives, prompting a removal trial in the Senate.

In such a trial, the Constitution simply requires two-thirds of the Senate , in this case 67 senators, to vote to convict and remove -- then it's goodbye Trump.

Trump's fate lies in the hands of 20 GOP senators -- the number needed to join the 45 Democratic senators and two independent senators, who normally side with Democrats, to vote to convict him and end his presidency, assuming they all vote to remove Trump.

Yes, it's a huge long shot that 20 Republican senators will vote to send Trump packing, especially given Senate Majority Leader Mitch McConnell's statement last week saying there's "no chance" that Trump will be removed. But as a former trial lawyer, I can tell you that jurors don't always do as expected. And there's always the possibility that more incriminating evidence is revealed about Trump between now and the start of the trial.

Even the most secure of US presidents would be unnerved at the prospect that their political demise is only 67 votes away. And while Trump has been called a lot of things, "secure" is not one of them. This is the same Trump who just days ago took to Twitter to despicably mock 16-year-old climate change activist Greta Thunberg, likely because she beat him out for the title of Time magazine's " Person of the Year ."

Adding to Trump's stress level are comments like the one made by former GOP Senator Jeff Flake, who recently declared that there would be "at least 35" Republican senators who would vote to remove Trump if ballots were kept secret. That number may be a bit high, but Democratic Sen. Chris Murphy stated a few weeks ago that he thinks there are at least five GOP senators already likely to vote with Democrats.

Any doubt that Trump is running this math through his head over and over, trying to figure out if he mocked or angered enough Republican senators that could spell his political doom? Of course, what gives Trump protection is that his GOP base backs him solidly, and any Republican senators who vote to remove Trump could expect to receive their wrath.

And while the Trump campaign publicly claims that impeachment will help Trump win in 2020 by firing up his base, Trump's own Twitter is a glimpse of a President in full panic mode. On Thursday, Trump unleashed a barrage of 123 tweets during the House Judiciary Committee debate on the articles of impeachment, many commenting on the hearings, including one instance where he accused two Democratic members of the House of lying.

That set a record for the most tweets by Trump in a single day, eclipsing his record of 105 tweets set just days before, on Sunday, where he also took aim at the impeachment process numbers.

For example, one of Trump's tweets Sunday expressed his approval of a conservative activist who had written , "The Constitutional framers would be appalled by the way impeachment is being wielded as a political weapon against President Trump."

By the following Friday, after the House Judiciary Committee voted to approve articles of impeachment, Trump again took to Twitter to express how upset he was: "It's not fair that I'm being Impeached when I've done absolutely nothing wrong!"

Even President Bill Clinton was apparently concerned at the possibility of being removed from office as evidenced by his apology to the country shortly after being impeached by the House in 1998, stating, "What I want the American people to know, what I want the Congress to know, is that I am profoundly sorry for all I have done wrong in words and deeds."

Clinton offered those words despite having an approval rating of over 60% at the time, which notably peaked at 73 percent just days after the House voted to impeach him.

Get our free weekly newsletter Sign up for CNN Opinion's new newsletter. Join us on Twitter and Facebook

What a contrast to Trump, who per FiveThirtyEight.com , currently has the lowest approval rating of any president these many days into his first term at 42%. Trump now even trails Presidents Jimmy Carter and George H.W. Bush at the same point in their respective first terms, and both of them lost re-election.

Trump should be worried. Anything can happen in a trial. All it will take is just 20 Republican senators to join the Democrats in saying they had enough of his antics, and Trump will have earned himself a place in history -- and in every school text book — as the first president in the history of the republic removed by the Senate. And that thought is clearly causing Trump to panic.

This article has been updated with the House vote on impeachment.