A mystery politician may be preparing to enter the 2016 presidential election. Political analyst Bill Kristol teased in a series of tweets over the weekend that an independent candidate will launch a bid against Hillary Clinton and Donald Trump, someone who is “impressive” and who has a strong team behind them.

Just a heads up over this holiday weekend: There will be an independent candidate–an impressive one, with a strong team and a real chance. — Bill Kristol (@BillKristol) May 29, 2016

Is Kristol right? Who could this candidate be, and could he or she actually have a shot at defeating Hillary Clinton and Donald Trump? Here are five fast facts you need to know.

1. Bill Kristol Is a Prominent Member of the #NeverTrump Movement

Weekly Standard editor and prominent Republican analyst Bill Kristol is one of the few members of the #NeverTrump movement who has still not come around on his party’s presumptive candidate. In fact, he said on MSNBC back in March that he would rather see Hillary Clinton elected than Donald Trump.

He has been speaking out against Trump for months, and back in December he went as far as to suggest the creation of a new party that republicans could start if Trump were to win the GOP nomination.

Crowd-sourcing: Name of the new party we'll have to start if Trump wins the GOP nomination? Suggestions welcome at editor@weeklystandard.com — Bill Kristol (@BillKristol) December 20, 2015

Since Trump became the presumptive nominee, Kristol’s Twitter page has been largely devoted to discussing the possibility of a third party candidate and throwing names out there. Recently, when Marco Rubio announced he would be supporting Donald Trump in the general election, Bill Kristol responded to him and called on the Florida senator to run as an Independent.

In Florida only 2 legitimate candidates on ballot in Nov. I wont vote for Clinton & I after years of asking people to vote I wont abstain. — Marco Rubio (@marcorubio) May 27, 2016

Why assume "only 2 legitimate candidates?" Filing deadline for independent candidate for FL ballot two months away. https://t.co/2PJOTMeoVI — Bill Kristol (@BillKristol) May 27, 2016

2. Trump Mocked Kristol in a Series of Tweets

Not long after Kristol’s tweet suggesting the emergence of an Independent candidate, Donald Trump took to Twitter to mock the commentator for his assertion, calling him a “dummy” and a “loser.”

Bill Kristol has been wrong for 2yrs-an embarrassed loser, but if the GOP can't control their own, then they are not a party. Be tough, R's! — Donald J. Trump (@realDonaldTrump) May 29, 2016

The Republican Party has to be smart & strong if it wants to win in November. Can't allow lightweights to set up a spoiler Indie candidate! — Donald J. Trump (@realDonaldTrump) May 29, 2016

If dummy Bill Kristol actually does get a spoiler to run as an Independent, say good bye to the Supreme Court! — Donald J. Trump (@realDonaldTrump) May 29, 2016

Trump is referring to the fact that over the past few years, Kristol has notably made many predictions that did not pan out, including that Barack Obama would not win a single primary in the 2008 election, that Joe Biden would enter the 2016 presidential race, and that Marco Rubio would win the New Hampshire primary. He also declared that Donald Trump’s candidacy had peaked 11 times since July 2015, although he was not the only pundit to underestimate the New York businessman.

This was hardly the first time Trump has mocked Kristol; he has done so in speeches as well, calling Kristol a “loser” during a rally in Anaheim last week.

Donald Trump Blasts 'Loser' Bill Kristol Trying to Start Third PartyWednesday, May 25, 2016: At a Trump campaign rally in Anaheim, CA, Donald Trump laid into Bill Kristol of The Weekly Standard. Donald Trump Blasts 'Loser' Bill Kristol Trying to Start Third Party 2016-05-25T20:17:13.000Z

3. Kristol Has Hinted Mitt Romney Might Run

One of the names Kristol has suggested for the third party bid is former presidential hopeful Mitt Romney. The Massachusetts governor has already taken his name out of consideration, but Kristol says that Romney is seriously reconsidering.

“The real last chance here is with Mitt Romney, who has said ‘no’ but who I think is thinking seriously about it,” Kristol explained. “[Romney] is a very serious person, he really knows that Trump should not be president of the United States. He strongly believes that Hillary Clinton should not be president of the United States.”

Indeed, Romney has been quite outspoken against Donald Trump, and he made a 17-minute speech back in March calling Trump a “phony” and a “fraud. He recently told The Wall Street Journal that his advisers begged him not to go after Trump, but he did so anyway so that he could “sleep at night.”

“I wanted my grandkids to see that I simply couldn’t ignore what Mr. Trump was saying and doing, which revealed a character and temperament unfit for the leader of the free world,” Romney said.

However, in that same interview Romney once again insisted that he will not enter the race.

4. Texas’ Filing Deadline Has Already Passed

In order for an Independent candidate to appear on the ballot in November, he or she must collect roughly 900,000 signatures and file paperwork in individual states by certain dates. If someone wants to throw their hat in the ring, then, they don’t have much time left; the filing deadline in Texas already passed on May 9, meaning Kristol’s hypothetical candidate already would not be listed on Texas’ ballot in the general election.

Each state has its own deadline, with some extending until the end of August, but there are several important dates coming up in the next few weeks. According to Ballotpedia, North Carolina’s deadline is on June 9th, and that state requires nearly 90,000 signatures. Illinois’ deadline is June 27th, New Mexico’s and Indiana’s are June 30th, and Georgia’s is July 12th.

5. The Last Successful Independent Candidate Ran in 1992

There is actually precedent for an Independent candidate doing well in the general election. In 1992, businessman Ross Perot ran as an Independent against Bill Clinton and George H.W. Bush, and he captured roughly 19% of the vote, translating into about 20 million votes cast in his name.

However, even in this unusually-successful campaign, Perot did not end up with a single electoral college vote and did not win any states. Perot also entered the race much earlier than Kristol’s candidate would; he announced his candidacy in February of 1992, nine months before the election.

Perot was the most effective third-party candidate since 1912, when Theodore Roosevelt ran in the Progressive Party and earned more votes than the Republican Party’s nominee, William Howard Taft.