Bernie Sanders cannot win the nomination, and there is a lesson in it for anyone looking to run at the local level. It has nothing to do with political ideology. Put simply: Voters don’t know him.

I am not going to discuss the science of polling. That is best left in this space to political science professor and BDN blogger Amy Fried, to whose expertise I defer. But as a political consultant, there is one poll tab that tells everything.

Media will report favorable ratings. But they do not matter. Nor do the unfavorable ratings. The key piece of information is how many people do not know enough about a candidate to form a favorable or unfavorable opinion.

When it comes to marking a ballot, voters will gravitate to someone they know, even unfavorably, over an unknown commodity.

A CBS poll issued the day before Tuesday’s first Democrat presidential debate reported that 44-percent replied that they did not know enough about Sanders to have a favorable or unfavorable opinion. Assuming the average voter who is not consumed with a daily diet of politics gives passing attention to the debate, his post-debate numbers will not change drastically enough to make a difference.

Love her or hate her, nearly everyone knows Hillary Clinton, and that gives her an advantage. It explains why, despite high unfavorable numbers, she leads as the first choice among likely voters.

During the 2012 elections, when I was doing political analysis on a Bangor television morning news program, I was able to predict almost exactly the percentage of the November vote for U.S. Senate in mid-June based to that poll tab.

Political junkies were the only voters paying close attention to the primaries. Despite all of the attention paid to them, a poll taken a few days after the primary showed that nearly half of respondents said they did not know enough about Republican Charlie Summers to form a favorable or unfavorable opinion.

Cynthia Dill, the Democratic nominee, was faced with more than 70 percent who said they did not know enough about her to have an opinion. Only 5 percent said they did not know enough about independent Angus King to have a favorable or unfavorable opinion.

That tab set the tone for the general election campaign. In that Senate race, for instance, King was free from the start of the three-way race to concentrate on his own message, while Summers and Dill had to expend campaign funds and time just to introduce themselves to voters in order to gain standing to articulate their views.

In our campaign boot camps, my partners and I preach to potential candidates repeatedly that a Nobody cannot challenge a Somebody.

In my book “The Politics Guy Campaign Tips – How to Win a Local Election,” I devoted a section to advising candidates to be involved in non-political community activities 18 to 24 months in advance of a general election just to establish their name recognition before they ever take out candidacy papers.

Even relatively well-known national figures can suffer from this name recognition issue. Jeb Bush’s campaign for the GOP presidential nomination is bogged in a quagmire. Part is attributable to his lackluster campaign style and part to ideological distrust from those to the right who are more prone to vote in primaries.

But a surprisingly large number respond to the favorable/unfavorable question that they do not know enough about him to form an opinion. Yes, they know the Bush family but not this specific individual. (I even encountered an otherwise well-informed Republican activist who thought he had been governor of Texas rather than Florida.)

That means that Bush will have to part with some of that campaign war chest to re-introduce himself and his background to voters. He will have to do it soon because post-nomination is too late.

Brent Littlefield deserves a lot of credit for his clever ad in the 2014 2nd Congressional District race for Bruce Poliquin. Despite GOP activists who knew him from prior primary runs for governor and senator, and a few Augusta insiders who knew him as state treasurer, average voters did not have enough information to form an opinion.

Littlefield crafted a basic biography ad, which in 60 seconds fleshed out Poliquin’s story from boyhood to Wall Street to State House. It was used early in the primary. But the campaign smartly ran it again at about the time general election voters were starting to pay attention.

Democrat Emily Cain was equally unknown despite her legislative work, and hardly anyone knew independent Blaine Richardson, allowing Poliquin to move into the next phase of campaigning.

In 2008, Barack Obama turned this unknown factor to an advantage. In his excellent primer on grassroots campaign organizing “The Audacity to Win,” campaign manager David Plouffe revealed that his team took a relatively obscure freshman senator from Illinois and ran an under-the-radar campaign targeting better-known candidates in Iowa and New Hampshire.

This then unleashed a tsunami of saturation coverage as media played catch-up to learn about upstart Barack Obama. His backstory got told with minimal expense to the campaign coffers.

Let this be a learning experience to all of the potential local candidates: Just because you get enough signatures to be on the ballot does not make you significant to voters.

You need to be out there right now, letting people get to know you and your background. Then, as a candidate, they will be more prone to listen to you and to take you seriously in their deliberations for casting a ballot.

Vic Berardelli is a retired political consultant and author of “The Politics Guy Campaign Tips – How to Win a Local Election.” Now an independent undeclared voter, he is a former Republican State Committeeman and former member of the Republican Liberty Caucus National Board.