A potential impeachment Senate trial for President Trump is the wildest wild card of all.

The fact is, no one really knows what a Senate trial might look like. And anyone who thinks they know how this could be a boon to one side or the other is truly kidding themselves. Sure, there might not be 67 votes to convict President Trump. That could be the one thing we do know. Everything else is way up in the air.

Conventional wisdom holds that a Senate trial would mimic the 1999 trial of President Bill Clinton. That’s hardly established. That trial featured no witnesses and a memorable closing argument delivered by the late Sen. Dale Bumpers, D-Ark., on behalf of the president. But during the lead-up to the trial, speculation was rife on Capitol Hill that senators may attempt to call Clinton to testify and even Monica Lewinsky as witnesses on the floor.

HOUSE INTEL COMMITTEE TO REVIEW DRAFT UKRAINE REPORT THIS WEEK

That never happened. That’s because then-Senate Majority Leader Trent Lott, R-Miss., and Minority Leader Tom Daschle, D-S.D., forged a pact for the structure of the trial. Lott and Daschle then presented the arrangement to the other 98 senators. All 100 senators agreed to the Lott/Daschle accord which limited the potential for salacious and tawdry testimony in President Clinton’s trial.

Reporters have peppered Senate Majority Leader Mitch McConnell, R-Ky., and Senate Minority Leader Chuck Schumer, D-N.Y., for weeks if they might meet to establish parameters for President Trump’s prospective trial. But no dice. No meeting yet. No agreement. And, even if McConnell and Schumer were to huddle, one wonders if they could even set an arrangement for a potential trial.

The Senate conducts much of its business via a parliamentary construct known as “unanimous consent.” In other words, if all 100 senators unanimously agree, the Senate can do just about anything. The Senate forges unanimous consent agreements to decide when to meet, when to vote and even to pass some bills. But, if one senator objects then that torches the proposal. That’s not unanimous consent.

In this environment, it’s hard to see how all 100 senators could agree to anything – especially establishing special ground rules for a Senate trial. That means that the Senate’s special rules for an impeachment trial would prevail. And that could be a free-for-all.

JUDICIARY COMMITTEE ANNOUNCES DECEMBER IMPEACHMENT HEARING, INVITES TRUMP TO PARTICIPATE

Let’s consider the possibilities for witnesses.

It’s customary in a Senate trial for the House to send to the Senate impeachment “managers.” These are House members who essentially serve as prosecutors and present the impeachment case to the Senate. One could certainly imagine where House Democratic impeachment managers would want to summon acting White House Chief of Staff Mick Mulvaney, acting White House Budget Director Russ Vought; Energy Secretary Rick Perry; former National Security Adviser John Bolton; attorney Rudy Giuliani; U.S. Ambassador to the European Union Gordon Sondland and perhaps even President Trump himself.

Wow.

For their part, Republicans may want the president to take the stand to defend himself against the House charges. And, GOPers would probably be all too hopeful to secure testimony of former Vice President Joe Biden, his son Hunter Biden, DNC operative Alexandra Chalupa (whom Republicans assert worked with Ukraine to dig up dirt on Trump campaign manager Paul Manafort), House Intelligence Committee Chairman Adam Schiff, D-Calif., and even the whistleblower.

Double wow.

There’s a term for such proceedings in Washington. The first word begins with “s” and the second word is “show.”

If senators can’t work out an agreement on how to conduct a Senate trial, then it’s up to U.S. Chief Justice John Roberts to decide who’s in and who’s out. The Chief Justice presides over such a trial. Late Chief Justice William Rehnquist had a rather passive role in President Clinton’s 1999 trial because Messrs. Lott and Daschle worked out things in advance. Here, it’s anybody’s ballgame.

In the 1999 trial, the Senate subpoenaed Lewinsky, Clinton confidant Vernon Jordan and White House aide Sidney Blumenthal. They provided videotaped testimony.

NEWT GINGRICH: PLOT AGAINST PRESIDENT IS REAL – AND BIGGER THAN MANY THINK

Forty witnesses testified at the Senate impeachment trial of President Andrew Johnson in 1868.

No one has any sense of the political consequences of such a scene. But a trial like this could lay bare some of the deepest divisions in American politics in a fashion never before witnessed. Democrats may relish the opportunity to query President Trump and Mulvaney. Republicans would be ecstatic to hear from the Bidens. But such a tableau is so extraordinary no one can gauge what this means for either party – especially in an election year.

And, imagine the impact such a scenario could have on Biden. And we haven’t even discussed the Democratic senators running for president and what this means for them – especially if the trial plays out in January and February. That’s primetime for these senators to be barnstorming through Iowa and sipping cups of joe at diners in New Hampshire. A trial will tether these presidential hopefuls to their desks in the Senate chamber. It’s unclear how Sens. Elizabeth Warren, D-Mass., Kamala Harris, D-Calif., Cory Booker, D-N.J., Michael Bennet, D-Colo., Bernie Sanders, I-Vt., and Amy Klobuchar, D-Minn., will handle such a bizarre campaign challenge. But watch for one factor: if one of these senators bolts the Senate to campaign, it’s likely they all bolt.

CLICK HERE FOR THE FOX NEWS APP

That said, their votes could be needed before a final judgment. Roberts doesn’t have to rule on every motion and question. Senate impeachment rules give the chief justice the option to “submit any such question to a vote of the members of the Senate.”

Republicans think a drawn-out process helps the president because it ties up the Senate and keeps Democrats off the campaign trial. A few GOPers also think that stretching things out shows the public what a political misstep it was for House Democrats to even impeach the president, triggering a Senate trial. Meantime, some Democrats believe an elongated process boosts their case – revealing alleged deep corruption in the Trump administration.

Also remember, we are operating in the era of Trump. That tells us two things: First, whatever conventions held before are out the door. Secondly, President Trump typically benefits from chaos. The crazier things are, the better it is for President Trump.

Trump always craves the spotlight. He did so on “The Apprentice.” In the defunct USFL. With New Jersey casinos. Golf courses in Scotland. His run for the Oval Office.

A Senate trial will be the biggest stage yet – and the most unpredictable.