Short of impeaching President Trump, does anything excite Democrats, the Resistance, and NeverTrumpers like the prospect of the president firing special counsel Robert Mueller? Firing Mueller would, of course, be the quickest way for Trump to get impeached, which might explain a certain air of anticipation in discussions of whether — some prefer to say when -- Trump will sack the prosecutor leading the Trump-Russia investigation.

There has been a lot of news and commentary recently interpreting criticism of Mueller by a number of pro-Trump media voices as an effort to encourage Trump to fire Mueller, or lay the groundwork for firing Mueller, or somehow start the process of getting rid of him.

"Overarching message to President Trump from pro-Trump talk shows: 'Mueller is out to get you. He must be stopped,'" CNN's Brian Stelter tweeted on Friday. In response, the NeverTrump former conservative radio host Charlie Sykes added, "Concerted effort to (1) discredit Mueller investigation, (2) lay groundwork for firing him."

"YOU'RE FIRED!" reads the anticipatory cover of the Weekly Standard, over a photo of Mueller.

There are plenty of other similar messages.

But there is another way to look at the recent wave of Mueller criticism: It's all politics. The overriding purpose of the anti-Mueller Trump defenses is not to goad the president into firing Mueller, which would be a disastrous act that could spell an early end to Trump's presidency. Instead, the overriding purpose is to discredit the Mueller investigation in the expectation that the probe will ultimately lead to articles of impeachment filed against the president in the House of Representatives. If that happens, and the impeachment goes to the Senate for trial, Trump, like President Bill Clinton before him, will have a ready, cable TV-tested line of defense focusing on the unfairness of the prosecutor. The audience for that defense would be Republican senators who will vote for or against the articles of impeachment.

Firing Mueller would be insane. Discrediting him is pure impeachment politics.

The current debate over whether Trump can be indicted for obstruction of justice is a sideshow. It's very, very likely Mueller subscribes to the view that the president cannot be indicted while in office and that impeachment -- a political process -- is the constitutionally-prescribed way of dealing with presidential misconduct.

That means it is far more likely that Mueller, if he felt he had evidence that could serve as the basis for impeachment, would write a report laying out that evidence. Justice Department regulations creating the special counsel office require that at the end of the investigation he give the attorney general "a confidential report explaining the prosecution or declination decisions reached by the special counsel." That report might be detailed, or it might be general, but if Mueller outlines any wrongdoing by the president, it will undoubtedly end up in the House Judiciary Committee, where articles of impeachment originate.

If Republicans control the House, it's highly likely that nothing will happen. If Democrats are in control, Trump could well be impeached. And if the House impeaches Trump, the Senate will hold his trial, where it will require 67 votes to convict and remove him from office. And that's where the discrediting will come in.

Remember the words of Bill Clinton. In the early days of the Lewinsky scandal, Clinton asked his pollster Dick Morris to survey whether Americans would want him impeached if he had lied under oath. Morris found that yes, the public would favor impeachment. To which Clinton famously replied, according to Morris: "Well, we'll just have to win, then."

Clinton's way to win was a furious and sustained attack on the judicially-appointed independent counsel, Kenneth Starr, and the federal prosecutors and investigators working for him.

On February 8, 1998, for example, a New York Times headline on the Lewinsky matter read: "President's Aides Expand Offensive to Counter Starr; Urging Inquiry on Leaks; Prosecutor Is Denounced as 'Corrupt' and Accused of Leading 'Witch Hunt.'" It's a headline that would have worked on many, many days in the Lewinsky battle.

Some of the attacks were silly -- as when Clinton ally James Carville called Starr a "nicotine-stained tobacco lawyer." Others were serious, as when Clinton pushed his own Justice Department to investigate the independent counsel. But silly or substantive, the attacks continued unabated until the Senate decided not to convict Clinton in February 1999.

The Senate trial, by the way, was a pointless exercise. The Senate's 45 Democrats decided in advance that they would under no circumstances vote to convict Clinton, which meant there was no way for Clinton's accusers to get 67 votes for conviction. When the House impeachment managers showed up with their case against the president, the Senate humored them for a while and then put an end to it. Clinton won.

Now, Trump allies are beginning to attack Mueller. They got a later start than Clinton's allies did, but they are also operating in a much faster-paced media environment than the Clinton era. They can catch up fast.

They also have another thing going for them: The Mueller team deserves some of the criticism it has been receiving. Not only does Mueller himself arguably have a conflict -- he has what has been called a close, "brothers in arms" relationship with former FBI Director James Comey, the key figure in the obstruction of justice part of the Trump-Russia probe -- but he has hired lawyers and investigators who actively supported and defended Hillary Clinton in recent times. The FBI's Peter Strzok was bounced from the Mueller investigation for anti-Trump and pro-Clinton texts exchanged with an FBI lawyer, who also left the Mueller Team. Top prosecutor Andrew Weissmann heaped praise on Justice Department official Sally Yates for defying Trump, and also attended Clinton's election-night "shattered glass ceiling" party in New York. Other Mueller prosecutors defended the Clinton side in the email investigation, and one, Jeannie Rhee, "defended the Clinton Foundation against racketeering charges, and represented Mrs. Clinton personally in the question of her emails," noted the Wall Street Journal's Kim Strassel.

"Imagine Dem response if Trump's personal lawyer hired to investigate Hillary," tweeted Andrew McCarthy, the former federal prosecutor who writes for National Review.

The bottom line: There's a case to be made against Mueller.

It's not possible to say whether the Trump strategy will work, or even be needed, because there are just too many moving parts at the moment. Mueller might not take any action touching directly on the president. The House might decline to impeach him. Even if the House did impeach, the Senate might pre-emptively make a trial moot, as it did in 1999. It's just impossible to know.

But there is one huge difference in the Clinton and Trump strategies, and it does not work in Trump's favor. Clinton attacked Starr from a position of popularity. Clinton's job approval rating was around 60 percent in the Gallup poll when the Lewinsky scandal began. It was about 68 percent when the Senate voted not to remove him from office. Impeachment is a political process, so of course Clinton was going to win.

It's an understatement to say Trump's numbers are nowhere near Clinton's. The president is at 35 percent job approval in Gallup now, and has never been higher than 45 percent. And along with that unpopularity -- driving some of that unpopularity -- is a hostile and negative press. (In the Lewinsky matter, much of the mainstream media megaphoned Clinton's campaign against "Inspector Javert" Starr.) Put low popularity and an unfriendly press together, and it seems unlikely Trump could set off any wave of public disapproval of Mueller the way Clinton did with Starr. Instead, if there were an impeachment trial, Trump would have to focus on raising doubt about the prosecutor's tactics among the 34 Republican senators he needs to vote to keep him in office.

That's what the attacks on Mueller are about. And that's why they will continue. Impeachment politics start early.