President Donald Trump’s decision to replace ineffectual White House Chief of Staff Reince Priebus with Homeland Security chief John Kelly — a former Army general with a history of smart, effective leadership — makes complete sense. What’s also worth noting is that Kelly is an honorable man, not a political hack or fixer.

Kelly got off to a fast start Monday with his decision to force out volatile, profane Communications Director Anthony Scaramucci after less than two weeks on the job. This may augur the arrival of a newly professional, well-organized, results-oriented White House.

That’s what everyone should hope. While Trump hating appears to be a full-time job for millions of Americans, the president has fateful decisions to make about health care, taxes, trade and environmental policies, and a foreign-policy minefield to deal with — only starting with North Korea’s belligerence and Russia’s provocations. If Kelly can get Trump to focus on these big-picture issues instead of his preoccupation with picking fights and score-settling on Twitter, that would be wonderful news.

Unfortunately, that’s a big if.

Trump, not Priebus, has been the primary cause of the administration’s turmoil and aimless drift. Unless the president accepts that he must focus, there’s only so much good a new chief of staff can do.