WHEN NEW YORK and Oregon sent urgent appeals to the federal government for N95 masks, which protect against coronavirus, days passed this month before they finally received shipments — of devices well past their expiration date and therefore useless for surgery and other acute-care settings. That drove home the increasingly clear point that the burden is on states to compensate for the federal government’s sluggish response to the gravest public health crisis in a century.

Some governors have been quick to take that lesson and run with it; others much less so.

In Ohio, Gov. Mike DeWine, a Republican, has been consistently proactive and prudent, shutting down a major festival and sporting events, closing schools statewide and shuttering bars and restaurants. He was initially slammed for overreacting; it wasn’t long before other governors followed his lead.

Meanwhile, Oklahoma Gov. Kevin Stitt, apparently taking his cue from President Trump’s weeks of minimizing the peril of looming pandemic, tweeted a photo of himself with his family at a crowded restaurant last Saturday — so much for social distancing. Amid a furor, the tweet was quickly deleted. But the governor’s office suggested Monday Mr. Stitt, also a Republican, is sticking to his routines, including going out to dinner with his family, “and encourages Oklahomans to do the same” — a statement that will stand as an example of witless leadership.

In Maryland, Gov. Larry Hogan has been focused and forward-leaning in addressing the emergency. He closed schools promptly and postponed the state’s presidential primary, scheduled for April 28, by five weeks. Mr. Hogan, a Republican, also directed state health authorities to prepare to add thousands more hospital beds to the state’s inventory, in part by reopening facilities previously closed — although officials later stressed that would be necessary only in a worst-case scenario. The governor banned tenant evictions for the duration of the crisis, and prohibited electric, gas, water, sewer, phone, cable TV and Internet companies from shutting off residential service or charging late fees.

Mr. Hogan and D.C. Mayor Muriel E. Bowser, a Democrat, also closed all bars, restaurants (except for takeout and delivery service), nightclubs, gyms and other public places. Gov. Ralph Northam of Virginia, a Democrat, has hesitated to go to that extreme — so far he’s encouraged restaurants, theaters and other businesses to stick to a 10-person limit — but it seems only a matter of time before he follows suit.

For governors, whose job description includes constant pro-business boosterism, the closures represent painful, counterintuitive acts of self-inflicted economic harm. They are nonetheless the responsible thing to do, in the cause of saving lives.

Belatedly, Mr. Trump has endorsed the warnings and recommendations of top infectious disease specialists. Yet the onus will remain on governors to devise mitigation measures and show leadership in this crisis.

Read more: