For more than a year — no matter who was doing the public polling — the results have come back the same: Republican Gov. Larry Hogan up by double digits in the Democratic bastion of Maryland.

Teachers have blasted his funding of the state’s schools and endorsed his Democratic opponent, Ben Jealous, in the general election. It hasn’t mattered.

Opinion writers have criticized his decision to kill Baltimore’s planned Red Line light rail. No effect.

A pro-Jealous political action committee has taken to the TV airwaves to run attack ads. No change.

In poll after poll, Hogan has led by an average of 18 percentage points over Jealous — in a state where Hillary Clinton easily defeated Donald Trump by nearly 30 points and Democrats outnumber Republicans 2-to-1. Even before the June primary that nominated Jealous, pollsters asked potential voters about a Hogan-Jealous match.

The polls indicate voters’ continued support of Hogan is due to their satisfaction with the direction of the state. But even the pollsters, themselves, say they are surprised with Hogan’s continued strength in blue Maryland, where Democrats traditionally mop the floor with the GOP.

Pollster Brad Coker of Mason-Dixon Polling & Strategy has surveyed the race three times in the past year and found Hogan leading by 16 points in September 2017, 17 points in February and 15 points last month.

Coker says he can’t believe Hogan will finish on Election Day with as big a lead as the polls show.

“I still see the undecided vote going more for Jealous than Hogan,” Coker said. “In the end, it may be 55-45 statewide. If it’s 20 points on Election Day, it means Larry Hogan is either the greatest governor in Maryland history or Ben Jealous is the worst candidate in Maryland history.”

Several pollsters also predicted the race would narrow in the state’s deep blue jurisdictions when new voters opt for Jealous and undecided Democrats who are currently skeptical of him return home to the party when they vote.

Such a shift could result in a continuation of historical voting patterns: No Democrat running for governor has received less than 40 percent of the vote since at least 1869. In 1966, George Mahoney turned in the worst performance on record for a Democrat when he got just 40.61 percent in his race against Republican Spiro Agnew — and that was a three-way race in which an independent siphoned off 9 percent.

Jealous has yet to break 40 percent of the vote in a public poll, while Hogan is performing well in the Democratic strongholds of the city of Baltimore and the Washington suburban counties of Montgomery and Prince George’s. Those jurisdictions are typically blowout victories for Democrats.

“It’s a sustained sanctification with the incumbent,” says Mileah Kromer, director of the Sarah T. Hughes Field Politics Center. “Hogan has been governor for 3 1/2 years. There’s been no real scandal. He has a record of working together with the Democrats. The economy in the state is doing well. When people say approval ratings don’t matter, this is the evidence to the contrary. Approval ratings do matter.”

A poll by The Washington Post and the University of Maryland this week found Hogan leading in traditionally liberal Montgomery County by 6 percentage points. A Goucher College poll last month had Hogan ahead by 5 points in Montgomery and Prince George’s. And a Gonzales Research & Marketing Strategies poll this week found Hogan only 10 points behind Jealous in deep blue Baltimore city (50 percent for Jealous; 40 percent for Hogan).

Kevin Harris, a senior adviser to Jealous, said he didn’t believe the polls were capturing the electorate that would materialize in the election. The Jealous campaign foresees a massive blue wave with over 1 million Democrats casting ballots that is unaccounted for in the polling.

“We don’t doubt he’s possibly ahead, but we do doubt he’s ahead by that much, and we doubt he’s doing that well in Baltimore city,” Harris said. “These polls are probably not properly capturing new voters, young people or minority participation. They’re not capturing the electorate that’s going to show up on Election Day.”

Harris notes that a lot can change in a race in the final weeks. Hogan trailed by double digits in a poll in the final month of his upset of Lt. Gov. Anthony Brown four years ago.

Scott Sloofman, Hogan’s campaign spokesman, said the polls show Marylanders are pleased with his boss’ performance and want to re-elect him.

“Every single general election poll has shown the depth and breadth of Gov. Hogan’s bipartisan coalition of supporters,” Sloofman said. “It goes to show that Gov. Hogan’s results-oriented focus on Maryland is what voters are yearning for in this era of political division.”

Kromer has polled Hogan’s lead at 13 points in April and 22 points in September. She says she can’t envision a Republican candidate performing so strongly on Election Day in Baltimore City and Montgomery and Prince George’s counties.

“That’s where you’re going to see the narrowing,” Kromer said of those three vote-rich jurisdictions. “I don’t believe for a second Larry Hogan is going to win by 20 points.”

But she said Jealous — who in the last finance report had $9 million less in campaign cash than Hogan — is running out of time to narrow the gap.

“The window is closing, and the polls suggest Jealous has a lot of ground to cover,” Kromer said. “Partisans do want to come home, but you’ve got to give people a reason.”

Pollster Patrick Gonzales has gauged Hogan’s lead at 13 points in December, 17 points in June, 16 points in August and 18 points this month.

“I don’t believe Larry Hogan wins Montgomery County,” he said, even though his own poll showed a tie there. “If, in fact, Hogan dead-evens Montgomery County, he’ll have a double-digit win” statewide.

The polls give indications for why Hogan has such continued strength in Maryland. In the Post/University of Maryland poll — which had Hogan leading by 20 points — Democrats gave the GOP governor a higher favorability rating than Jealous by 59 percent to 52 percent.

That poll also found Marylanders prefer Hogan to Jealous by double-digit margins on a variety of issues that Jealous has tried to turn to his advantage, including the economy, education and health care. The Goucher Poll found that more Marylanders than not say they’re doing better financially than in the past. And voters said they trusted Hogan more than Jealous to handle the state’s biggest issues, including the economy (66 percent to 23 percent), education (51 percent to 36 percent) and health care (51 percent to 35 percent).

Gonzales’ latest poll found 64 percent of those surveyed said they thought Maryland was moving in the right direction, while just 20 percent said the state was off track.

Those results “make it difficult for somebody running as a change agent,” Kromer said. “It’s difficult to break through when people are satisfied with how things are going.”

Both Coker of Mason-Dixon and Gonzales said the consistency of Hogan’s poll results said more about the Republican governor’s set image in voters’ minds than his challenger’s deficiencies.

“Whenever you have an incumbent on the ballot, it’s always a referendum on the incumbent,” Gonzales said. “In that way, the numbers have always said that voters overall in Maryland are kind of satisfied.”

Harris, of the Jealous campaign, noted Hogan and his allies at the Republican Governors Association have spent nearly $8 million in television advertising, but haven’t noticeably widened their lead. Harris said he anticipated being outspent about 5-to-1 by the time the race was over.

Harris noted other data points favored Jealous and indicated a surge for the Democrat. For instance, absentee-ballot requests have risen among Democrats.

“There have been 66,067 absentee ballot requests sent in through Friday, Oct. 5, with 65 percent of those requests coming from registered Democratic voters,” Harris said in an email. “This is a huge 103 percent increase over the 32,527 requested ballots at this point in 2014.”

Baltimore Sun reporter Michael Dresser contributed to this article.

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