If there is one figure in the latest Siena College poll that explains incumbent Byron W. Brown’s commanding lead in Tuesday’s Democratic primary for mayor, it may very well be the 78 percent of respondents who say Buffalo is on the right track.

Just about all the poll’s other statistics – Brown’s 70 percent favorable rating, the 63 percent who approve of his job performance, and the 2-to-1 lead over his challenger – stem from the belief of so many that the city’s overall picture looks bright.

“This is a phenomenal number,” pollster Steven A. Greenberg said of the 78 percent who see the city headed in the right direction. “That’s why the mayor is in front.”

The latest Siena Research Institute poll conducted last week for The Buffalo News and WGRZ-TV/Channel 2 shows that Brown leads Bernard A. Tolbert 63 to 30 percent among Democrats likely to vote Tuesday in the primary.

The percentage of voters viewing Buffalo as on the right track has increased substantially since the last Siena poll in August, Greenberg added. That survey showed 56 percent thought the city was headed in the right direction.

But Greenberg also noted the latest “horse race” measurement showing has not changed substantially from the 61 to 32 percent tally measured in August.

Brown’s favorable rating have also increased, however, from 58 to 70 percent in the last three weeks. Tolbert’s favorability rating also has improved, from 39 to 46 percent.

“What has changed is that Brown’s favorables have really skyrocketed,” Greenberg said. “Tolbert is also becoming more well known but not necessarily more well liked.”

Following a string of endorsements from top New York Democrats, a flurry of positive advertisements, and even one spot featuring high praise from the president of the United States (filmed during President Obama’s recent speech at the University at Buffalo), Brown enters the last days of the primary campaign with a lead that poses a huge challenge for Tolbert.

And while the challenger is now recognized by many more voters and 46 percent view him favorably, Tolbert still trails in just about every demographic.

Brown leads among black voters, for example, 82 to 12 percent, and among whites 53 to 41 percent. Significantly, the poll also shows that 90 percent of those surveyed believe Brown will win the primary election on Tuesday.

“I am hard-pressed to see how 90 percent of the people can be wrong,” Greenberg said.

Tolbert said late Saturday the poll results do not jibe with the reaction he gets every day from citizens he visits on the streets of Buffalo.

“They tell me they’re glad I’m running and it’s time for a change,” the challenger said. “I don’t know how to match that with what the polls say.”

Tolbert, former special agent in charge of the Buffalo FBI, also questioned the poll’s indication that 78 percent of those surveyed see the city as on the right track. He said the lofty figure may stem from the perception that “things have been bad for a long time.”

“I don’t quite hear that when I talk to folks,” he said. “The refrain I get is that crime is a huge problem.”

Brown, meanwhile, said he was most heartened by the “right track, wrong track” figure.

“To see 78 percent of those polled say Buffalo is on the right track makes me feel proud of the work we’ve done and continue to do,” he said, attributing such approval to such tangible signs as construction cranes on the waterfront and at the Buffalo Niagara Medical Campus.

“Clearly, people see the progress we’ve made,” he said. “It’s tangible, it’s bricks and mortar, it’s real.”

The poll, which surveyed 502 Buffalo Democrats who are likely to vote, was conducted Tuesday through Friday and has a margin of error of plus or minus 4.4 percentage points. Greenberg pointed out that results have varied only slightly through the three surveys conducted for The News and Channel 2, but that the latest carries the most weight following a round of debates (one televised), a blizzard of television ads by both candidates, and the fact that most voters are now engaged in the campaign at summer’s end.

The polls shows education remaining the most pressing issue for those planning to vote on Tuesday, coming in first at 29 percent. Tolbert has rightly put that issue at the top of his agenda, Greenberg said, but his other top issue – crime – ranks fourth at 19 percent.

Jobs (20 percent) and economic development (24 percent) rank ahead of crime, though crime ranks second on the list for Tolbert voters at 28 percent.

The survey also indicated that the vast majority of Buffalo Democrats – 76 percent – are satisfied with the choices of Brown, Tolbert and Republican Sergio R. Rodriguez as candidates for mayor.

Rodriguez will face the winner of the primary election in November.