Maryland Gov.-elect Larry Hogan, a Republican, receives a call from New Jersey Gov. Chris Christie after beating Democrat Anthony Brown, not pictured, in the state's gubernatorial race Wednesday, Nov. 5, 2014 in Annapolis, Md. (Steve Ruark/AP)

LARRY HOGAN’S long-shot, come-from-behind victory in Maryland’s gubernatorial race was a stunner. It was a credit to the Republican’s disciplined and strategically deft campaign as well as his amiable manner. It also was a direct repudiation of the administration of Gov. Martin O’Malley, a Democrat whose hand-picked successor, Lt. Gov. Anthony G. Brown, entered the race as something close to a prohibitive favorite only to squander a sizable lead.

Because the contest was cast by Mr. Hogan and his fellow Republicans as a referendum on Mr. O’Malley and his tax-and-spend policies, Mr. Hogan was able to avoid putting forward an agenda of his own. This race was a negative one, and Mr. Hogan, in the role of chief critic of the last eight years of Democratic rule in Annapolis, was able to make the more convincing negative case.

That case rested on the proposition that, even in a liberal state, there is a limit to the tax increases that people will accept. In Mr. Brown, the Republicans had the perfect foil — tightly scripted but devoid of any compelling rationale for his campaign beyond a proposal for universal pre-kindergarten for 4-year-olds, for which he offered no plausible way to pay. In the end, Mr. Brown acceeded to Mr. Hogan’s signature issue, saying he, too, would never raise taxes.

As he hammered the O’Malley-Brown administration on taxes, however, Mr. Hogan paid scant attention to crafting a coherent platform. To draw a stark contrast with the O’Malley-Brown administration, Mr. Hogan said he would gouge $1.75 billion in “savings” from the state budget, with which he would cut taxes, spur economic development and jump-start job creation. Under scrutiny, the savings he claimed could be found by slashing waste and abuse evaporated like fairy dust. It didn’t help that Mr. Hogan’s math turned out to be sloppy; his own running mate, Boyd Rutherford, acknowledged that “mistakes were made” in formulating the proposed savings.

The result is that Maryland has a governor-elect who has yet to put forward an implementable agenda.

The good news is that Mr. Hogan’s victory marks an interruption of Democratic hegemony in Maryland. Despite their still-enormous margin of control in the General Assembly, Democrats are on notice that they do not rule by fiat in a one-party state.

The other good news is about Mr. Hogan himself. We endorsed him in the GOP primary because he seems to be, by temperament and conviction, a genuinely moderate Republican, disinclined to play culture war politics. With the possible exception of his fuzziness on gun rights — he was endorsed by the National Rifle Association but refused to make public his stand on the issues the group asked him about — there is nothing to suggest he plans to pursue divisive social issues.

Rather, Mr. Hogan campaigned on a promise to rebrand Maryland as a more hospitable place for business. That means reinvigorating a state economy imperiled by the cuts sequestration has forced in federal spending. Having campaigned as a centrist, he now has the opportunity to govern as one.