Let’s face it — this has probably been true ever since the evening of November 6th. Recent filings by Robert Mueller might point to growing vulnerabilities for Donald Trump since then, but his biggest liability is the loss of Republican control in the chamber where a simple majority can impeach a president.

His biggest asset? Republican control in the chamber where it takes two-thirds to remove one:

Despite President Donald Trump’s public declaration that he isn’t concerned about impeachment, he has told people close to him in recent days that he is alarmed by the prospect, according to multiple sources.

Trump’s fear about the possibility has escalated as the consequences of federal investigations involving his associates and Democratic control of the House sink in, the sources said, and his allies believe maintaining the support of establishment Republicans he bucked to win election is now critical to saving his presidency. …

“The entire question about whether the president committed an impeachable offense now hinges on the testimony of two men: David Pecker and Allen Weisselberg, both cooperating witnesses in the SDNY investigation,” a close Trump ally told NBC News.

That misses the mark. It hinges more on the decisions of two other people — Jerry Nadler and Nancy Pelosi. Do they want to pursue impeachment over a questionable case of FEC violations for the purpose of covering up two or more tawdry extramarital affairs, twenty years after arguing that perjury and obstruction of justice to hide an extramarital affair wasn’t legitimate grounds for impeachment? Do they want to risk their newly won House majority on an effort that spectacularly backfired on Republicans in 1998?

They just might, but if so, they would have done so even before yesterday’s filings from Mueller. Trump ain’t Bill Clinton when it comes to popularity, and times have changed enough so that calling women “bimbos” and making reference to trailer parks won’t sway public opinion in Trump’s favor. Even so, this step is no political slam dunk, and the Democrats’ own track record of personal vituperation against Trump will make it look very much like retribution. That will be especially true if they’re forced to pursue this line of impeachment in the absence of anything more significant from Mueller’s investigation into purported Russian collusion.

As House Judiciary chair, the decision falls to Nadler whether to pursue articles of impeachment, and even he expressed some reservations this week as to whether FEC violations rose to that level:

TAPPER: Can you explain what you mean when you differentiate between, maybe these are — if it’s proven, it’s impeachable offenses, but that does not necessarily mean that the offenses themselves are important enough to actually begin proceedings of impeachment? There seems to be a difference there, in your view. Why?

NADLER: It’s not necessarily a difference. But it’s simply two different considerations. You don’t necessarily launch an impeachment against the president because he committed an impeachable offense. There are several things you have to look at. One, were there impeachable offenses committed, how many, et cetera? And, secondly, how important were they? Do they rise to the gravity where you should undertake an impeachment? An impeachment is an attempt to, in effect, overturn or change the result of the last election. And you should do it only for very serious situations. So, that’s always the question.

Democrats have tried to help Nadler make a case for impeachment by hyping this up as Trump’s attempts to “defraud” the electorate by preserving … what, exactly? His sunny image as a faithful husband? Former Bush adviser and current CNN contributor Scott Jennings scoffs at this idea in an essay for USA Today, emphasizing that the payoffs didn’t cover up anything that wasn’t already widely known about Trump. Or, for that matter, widely promoted by Trump:

First, the idea that Trump was trying to conceal from the world that he cheats on his wives is laughable; his infidelity is part and parcel to the “playboy businessman” image Trump carefully cultivated for decades! Do prosecutors honestly believe that one single voter was unaware of Trump’s promiscuity?

They would have to explain to a jury that if voters could have heard from just two more women about their sex with Trump, the outcome of the election would have been different. For goodness sake, Trump once engineered a cover story in the New York Post headlined, “Best sex I’ve ever had,” purportedly words spoken by Marla Maples!

Second, it is highly likely that Trump has been paying women he has slept with (and other people for other reasons) for years as part of nondisclosure agreements. His lawyers will argue that the payments are routine business expenses for a man who has a lot of sex and pays for a lot of silence, whether he’s running for office or not.

So why cover it up at all? Jennings says to follow the money:

Finally, what do you want to bet Trump’s actual motivation for making the payments had more to do with keeping Melania Trump from finding out more than any voter? Trump surely has a prenuptial agreement that gets much worse for him if he’s unfaithful. Plus, Trump admitted after the election he thought he was going to lose, which caused him to rent a smaller ballroom for his election night party. Trump’s lawyers will argue that their client thought his candidacy to be a lost cause, but not his marriage.

“If you want to impeach the president,” Jennings advises Nadler, “go for it. But don’t insult the Constitution’s demand for high crimes and misdemeanors with this campaign finance flimflam.” Jennings won’t be the only one seeing this as a partisan retaliation, either, if Mueller returns a goose egg on Russia. Furthermore, there will be zero chance of a GOP-controlled Senate removing Trump over some FEC violations, let alone getting two-thirds of the chamber to vote for removal.

And if Mueller comes up empty on Trump over Russia, that means Nadler and Pelosi will face a big dilemma. What suits their purposes better: a damaged Donald Trump and a GOP unable to remove him from a 2020 ticket on the basis of what’s already known, or an energized GOP base for 2020 looking to punish Democrats for using impeachment to score political points? Republicans from 1998 know the answer to that question.

Of course, this all changes if Mueller does find impeachable offenses relating to Russian interference in the 2016 election cycle. Impeachment would be a slam dunk for Democrats, but it still might leave them vulnerable. They would still have to ask themselves if they’d be better off leaving a damaged Donald Trump stuck on a GOP re-election ticket, or a President Mike Pence with a clear shot at establishing a calming incumbency. Both Al Gore and the late Gerald Ford might have had some advice on that question, if it ever comes to that point.