X-factors are outside forces and events that can upend elections and are beyond the control of candidates and campaigns. Think James Comey’s announcement in the waning days of 2016 that the FBI was again investigating Hillary Clinton’s emails.

This year’s X-factor is Trump. But is he magic – or toxic?

Clearly, 2016 has him intoxicated. He believes Republicans win if he drives his base to the polls. He’s also driving Democrats to the polls. But where is he driving Independents and swing voters?

This T-factor can cause wild swings Tuesday night. Conventional wisdom has settled on a consensus estimate: Democrats win the U.S. House and Republicans hold the Senate; North Carolina Democrats break at least one supermajority but don’t win a majority.

But probabilities are not predictabilities. Remember the analysts who were 97 percent certain Hillary would win. Smarter observers put her odds at 60-70 percent. That’s still a 30-40 percent chance something else could happen. And it did.

Every day, Trump dominates the news. He leaps into every fight and every story: mail bombs, synagogue murders, immigrants, health care, the stock market. He’s done more than nationalize the elections. He’s personalized them.

Two years ago, the Trump tide surprised everybody, maybe even Trump. Is there a hidden Trump tide this year? And which way is it running?