Larry Hogan's 5-point defeat of Lt. Gov. Anthony Brown last week in the Maryland governor's race was overshadowed by national electoral developments, notably the Republicans' recapture of the U.S. Senate majority they lost in 2006. But what a win.

Just four years after Democratic Gov. Martin O'Malley's 14-point victory over former Gov. Bob Ehrlich in 2010, Mr. Hogan's victory in this otherwise solidly blue state was a stunning reversal of the two parties' fortunes. Plenty of people, including myself, underestimated how formidable a candidate Mr. Hogan would be.

Mr. Hogan ran a focused campaign with a consistent message. He demonstrated a strong command of state policy, and used his Change Maryland platform to first separate himself from the field of Republican challengers in the primary, and then beat Mr. Brown in a state where Democrats enjoy a huge partisan registration advantage.


Congratulations and well done, Governor-elect.

Mr. Hogan's remarkable victory was less about turnout than conversion of the Maryland electorate. He persuaded independents and moderate Democrats to support him and, if we're being honest, race played at least some role in this transformation.

Let me explain what I mean.

To begin, the share of votes cast by key counties was roughly the same in both 2010 and 2014.

The Democratic jurisdictions delivered their expected proportion of voters, so Mr. Brown's loss was not a matter of low turnout. Sure, the Democrats' "Big 3" jurisdictions — Baltimore City, plus Montgomery and Prince Georges counties — continued to shrink in clout, slipping from 37.2 percent of all 2010 voters to 36.7 percent this year. Meanwhile, reviving a term I coined for The Sun in 2002, the "New Big 5" counties of Anne Arundel, Baltimore, Carroll, Frederick and Howard ticked up slightly, from 39.6 percent of voters four years ago to 41.2 percent in 2014.

These small geographic shifts hardly account for the nearly 10-point net partisan plunge from Mr. O'Malley's 57.4 percent share of the two-party vote in 2010 to Mr. Brown's 47.8 percent last week. Rather, the gubernatorial contest was a conversion election: Compared to Mr. Ehrlich's two-party share in 2010, Mr. Hogan improved in all 24 jurisdictions.

The county-level results varied significantly, however, ranging from Mr. Hogan's low-end, 3.7 percent increase over Mr. Ehrlich's 2010 performance in Prince Georges County to a top gain of 16.6 percent in St. Mary's County. And a closer look reveals a racial pattern: Mr. Hogan's four smallest county-level gains — in the Big 3 counties, plus Howard County — occurred in the six least white counties in Maryland, whereas the state's 10 whitest counties produced five of Mr. Hogan's 10 largest gains.

With a correlation coefficient of 0.62, Mr. Hogan's county-level improvement and the counties' white population share were strongly and positively correlated. Notice, too, that the two white statewide Democratic candidates in 2014 were easily elected to be comptroller and attorney general.

Before the angry emails pour in, let me be clear: I'm not suggesting Mr. Hogan's victory is tarnished. He did not racialize the election. As I said, he ran the better campaign and very smartly capitalized on statewide and national dissatisfaction. He deserved to win.

But it also deserves to be noted that, while impossible to calculate precisely, somewhere between 100,000 and 200,000 presumably white Marylanders who pulled the lever for either Mr. O'Malley, Doug Gansler and Peter Franchot in 2010, or Mr. Franchot and Brian Frosh this year, did not support Mr. Brown's bid to become Maryland's first black governor.

Nevertheless, black or white, state Democrats long comfortable with one-party rule owe Mr. Hogan a full hearing on issues related to Maryland's business environment, taxes and regulation — especially as they affect the state's small-business community. If, however, Mr. Hogan turns out to be the corporate lackey the Brown campaign tried to depict him as — or if the new governor backtracks on his promises to govern as a social issue moderate — Democrats should push back aggressively.

For now, Mr. Hogan should be taken at his word that he will work with Democrats in the state legislature in a bipartisan fashion to solve state problems. Last week he attracted the votes necessary to win, and now he commands our full attention.

Thomas F. Schaller teaches political science at UMBC. His column appears every other Wednesday. His email is schaller67@gmail.com. Twitter: @schaller67.