If Mitt Romney wanted to grab our attention, he has succeeded.

With Romney not yet sworn in as a Republican U.S. senator for Utah, it's far too early to know exactly what to make of his decision to publish a blistering op-ed in The Washington Post on Tuesday night, denouncing the character of the president and head of his own party, promising to oppose White House priorities when he disagrees with them, and declaring his intention to "speak out against significant statements or actions that are divisive, racist, sexist, anti-immigrant, dishonest, or destructive to democratic institutions."

Perhaps it will mean very little. Maybe Romney will follow the leads of Republican Sens. Jeff Flake (Ariz.), Bob Corker (Tenn.), Ben Sasse (Neb.), and the late John McCain (Ariz.) in furrowing their brows, delivering grave, civic-minded speeches from the well of the Senate about Donald Trump's norm-violations, and then voting in near-lock-step with the president's agenda.

But that is unlikely.

The most likely reason Romney has chosen to fire a shot across the president's bow at this moment, less than two days before he takes his Senate seat, is that he wants to set himself up as the de facto leader of the (sizable but mostly silent) faction of the Republican Party establishment that still stands strongly opposed to Trump as a person and as a president.

Romney is uniquely poised to take on that role in a formidable way. Unlike Flake, Corker, or Sasse, he's a former presidential nominee of his party with near-universal name recognition. This loudly amplifies his critical statements about the president and gives them considerable weight. He's also fabulously wealthy and has just been elected to a six-year term that will end when he's 77 years old — two factors that could free him up to speak his mind in a way that few elected officials are willing to do. On the other hand, if Romney is contemplating a primary challenge to Trump next year, the Senate could be an ideal place from which to launch it.

But it may well be that Romney's only motive is doing what he deems to be right. That might sound naïve in our age of all-pervasive political cynicism, but recall the brutal speech attacking Trump and his campaign that Romney chose to deliver on March 3, 2016. There was no reason for him to launch that broadside beyond the conviction that Trump was unfit to serve as president and the desire to do something about it.

The real question is what "do something" will mean in the present context.

Back in 2016, Romney's speech made a lot of Washington waves, but it did little to slow Trump's momentum toward clinching the nomination. A long litany of critical remarks by those four previously mentioned anti-Trump senators have been equally ineffective. And as countless liberals began angrily pointing out on Twitter Tuesday night within minutes of the op-ed's appearance, those words have seldom translated into action against the president and his agenda. That has already led many to conclude that Romney's grand rhetorical stand against the president will be equally performative, winning him plaudits in the press while the Trump agenda rolls on unobstructed.

But this is both terribly short-sighted and myopically partisan.

For one thing, the standard for judging Romney's opposition to Trump can't be what a Democrat in Republican clothing would do. Trump's judicial nominees, for example, are drawn from the same pool of conservatives from which a President Romney would select his own appointments to the federal courts. That means nothing Trump does will inspire Romney to oppose the president's nominees. The same holds for additional cuts to taxes and regulations. Those are bedrock priorities for Republicans of both the Trumpist and establishment wings of the party, so it's foolish and unfair to expect Romney to mount a challenge to the president on those issues.

But in other areas — immigration, trade, foreign policy — active opposition from Romney is more likely. The same holds for the president's most intemperate tweets denouncing the press and demonizing minorities. Romney vowed in his op-ed to speak out when the president gives in to his inner demagogue, and that's something all of us should welcome. Words matter, and we could use more articulate defenders of decency on the political right in this country.

Perhaps most significant of all could be the role Romney plays in the Senate once Special Counsel Robert Mueller issues his report on possible collusion between Russian and the 2016 Trump campaign, not to mention the many other ongoing investigations of financial improprieties in the Trump organization. The Democratic majority in the House will be much more likely to impeach the president if it has reason to believe there's a chance that 20 or so Republican senators might be persuaded to join the Democratic minority in the Senate in voting for conviction and removal from office. Having an outspoken and widely respected critic of the president in the chamber can only make that more likely. It will also give Romney enormous leverage in negotiating with the White House on other issues.

All told, Romney's op-ed is a big deal. It's a sign that the civil war in the GOP that so many pundits talked about during the 2016 election cycle isn't over yet. The battle for the soul of the party goes on. And Mitt Romney has now placed himself firmly on the front lines of the side arrayed against Donald Trump.