Maryland Gov. Martin O'Malley and Lt. Gov. Anthony Brown, shown in 2008. Brown has pointedly avoided mention the incumbent as he campaigns for governor. (Ricky Carioti/The Washington Post)

Maryland’s first gubernatorial debate Tuesday yielded no clear-cut winner but did serve up one obvious loser: Gov. Martin O’Malley (D).

With a new Washington Post poll showing O’Malley’s popularity has suddenly plunged, the Democratic candidate, Lt. Gov. Anthony Brown, pointedly avoided mentioning the incumbent.

Brown’s reticence was striking, given that he owes his nomination almost entirely to being O’Malley’s handpicked political protégé.

By contrast, Republican candidate Larry Hogan repeatedly brought up O’Malley’s name. He warned voters that electing Brown would mean more tax increases and tepid economic growth of the sort that have helped turn the public against O’Malley.

I think voters are fickle and too quick to forget all the good things O’Malley did before he went off to run for president. These include investing in education, protecting the environment, tightening gun controls and approving same-sex marriage.

But Brown’s posture in the debate, reinforced in a telephone interview with me Wednesday, highlights an important shift within the leadership of the state’s dominant Democratic Party.

Brown and his running mate, Howard County Executive Ken Ulman, favor a more pro-business, tax-averse strategy for the economy than the one championed by O’Malley in nearly eight years in office.

It’s a politically convenient position right now, so voters have every right to treat it with skepticism.

Still, although he’s done little to publicize it, Brown has a record of moderate, pro-business policies that distinguish him from the governor.

“Brown is really more of a pragmatist,” Todd Eberly, chairman of the political science department at St. Mary’s College, said. “He would be a more moderate to centrist governor than O’Malley has been.”

Brown was an early supporter of the Intercounty Connector, which local businesses favored and environmentalists opposed. He was a leading champion of a bill, now a state law, that made it easier to create public-private partnerships to expand business’s role in projects such as the Purple Line.

I mentioned those positions and others to Brown in the interview, and said I thought overall he was more moderate and business-friendly than O’Malley.

“I think you’re accurate,” he responded.

“I don’t use the label, ‘pro-business,’ because it has too many connotations that I may not necessarily subscribe to,” Brown said.

But he stressed: “The first strategic goal of the Brown-Ulman administration will be to position Maryland’s business climate to be No. 1 in the nation.”

No. 1 is wildly unrealistic, considering that Maryland has typically ranked in the low 40s. It’s telling, however, that it’s Brown’s top stated objective.

The change is most evident in Brown’s new, categorical promise not to raise taxes or fees if elected.

During the primary, Brown would only say that he saw no need for tax hikes. Now he’s ruling them out entirely, and did so three times in the first 10 minutes of the debate.

“I haven’t seen the need for quite some time, so let me be clear on what that means,” Brown said in the interview. “There will be no new taxes and fees.”

That’s quite a departure from O’Malley. The governor likes to say that while he hates raising taxes as much as anybody else, they’re a necessary price for quality public services. If you don’t want taxes, he suggests, then move to Somalia or Mississippi.

That philosophy is not satisfying the public. The poll found taxes to be the No. 1 issue for a plurality of Maryland voters, ahead of education and jobs.

The unhappiness over taxes explains why Brown’s lead over Hogan in the poll was smaller than one would expect, given the Free State’s deep blue political hue. Brown was ahead by just nine percentage points, in a poll in which registered Democrats outnumbered registered Republicans by 29 points.

Hogan has made taxes the centerpiece of his campaign, repeatedly pounding the “O’Malley-Brown administration” for 40 increases in taxes and fees.

He also has forced Brown into an awkward dance. The lieutenant governor is trying to separate himself from O’Malley on some issues without looking disloyal or alienating the party’s liberal base.

“It’s not a distancing in a sense of running away,” Brown told me. “It’s the necessary effort to clearly define my positions, my views, my values.”

The polls suggest Brown will succeed O’Malley as governor. In the rest of the campaign, including the two remaining debates, the public should demand that he be explicit about how his positions vary from the man he’s served for nearly eight years.

I discuss local issues Friday at 8:50 a.m. on WAMU (88.5 FM). For previous columns, go to washingtonpost.com/mccartney.