The truculent, if low-profile, aide represented a divisive presence within the West Wing. Bannon battled continuously with perceived opponents of his "nationalist" agenda. Though he had only limited success, National Economic Council Director Gary Cohn and National Security Adviser H.R. McMaster can now perform their jobs with less interference.
But that will not resolve the issues that preceded his departure.
Bannon may have championed the so-called "alt-right" that provoked deadly violence in Charlottesville. But it was Trump's long-held views, not his aide's influence, that led the president to express sympathy for torch-bearing marchers. That became clear this week when an unscripted Trump returned to his initial "both sides" formulation on Monday, after reading a stage-managed denunciation of white supremacists and neo-Nazis.
Moreover, Bannon has the ability if he chooses to make more trouble for the "establishment" Republican agenda outside the White House. An editor at Breitbart, the far-right news site he formerly ran, tweeted "#WAR" as news of Bannon's ouster broke.
If Bannon returns to Breitbart and follows through on that threat, he could roil the Republican base at a time when the GOP needs unity to enact its agenda on tax reform and other issues. That would pose problems not only for Trump's "globalist" advisers, but also for Republican lawmakers as they seek to hold the House and Senate in next year's mid-term elections.
Yet Bannon told Bloomberg News that he was planning to go to bat for Trump. "If there's any confusion out there, let me clear it up: I'm leaving the White House and going to war for Trump against his opponents -- on Capitol Hill, in the media, and in corporate America," he said to the publication.
As President George W. Bush's former political director Sara Fagen said on CNBC today, outsiders often exaggerate the importance of individual White House aides — even the most prominent ones. Bannon did not succeed in persuading the administration to shield its tax plan from Democratic attacks, by proposing an increase in the top personal income tax rate.
He did not succeed in advancing a tax on imports to protect American-manufactured goods. By his own account, he craved a trade war with China. But so far, the Trump White House has offered mainly bluster.
The core problems that have driven Trump's job approval ratings below 40 percent and alienated GOP Congressional leaders and international counterparts stem from the president himself: His selfishness, impulsivity, inattention and ignorance.
By his words and actions, he has shown that he values neither truthfulness nor the moral distinctions between right and wrong for which Americans have traditionally looked to their president.
That's why Republicans on Capitol Hill expressed somewhat less hope than investors did when stocks rose today as news of Bannon's departure broke.
"Probably helps functionality of the White House, but it doesn't change Trump," one top GOP strategist said.
"Not sure [it] makes much of a difference unless it turns out [Bannon] was ghostwriting all the self-immolation tweets," said another.
A senior White House official gave me a similar assessment of Bannon's exit. "Most people wondered what he did beside leak in an unending defense of himself," the official said.
Now the question is whether he turns up the volume against his adversaries from the outside.