Insurance. You have it and hope you never use it. But, just in case, it’s always there.

Joe Biden is insurance for Democrats in 2020. Yes, Biden is the frontrunner in the polls. Yes, many people think Biden will be the nominee. But if Biden doesn’t perform then Democrats will pick another candidate to challenge Donald Trump. In the meantime, Democrats will keep supporting Biden to make sure he’s in the strongest position, if he is the nominee, to take on the president.

So just how strong is Biden? Let’s go to the numbers.

In the latest Fox News Poll, published on Aug. 15, Biden leads the Democratic field with 31 percent. That’s an 11-point lead over Elizabeth Warren, in second place with 20 percent, and third-place Bernie Sanders at 10 percent. At first blush that looks like a strong position for Biden. However, Biden was at 31 percent in the March Fox News Poll … five months ago. Biden had a four-point bump to 35 percent in May, dropped in June to 32 percent, gained one point in July, and then back to 31 percent in August. Steady but hardly the numbers of a strong frontrunner.

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Let’s look at the general election matchup with Trump.

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Today, Biden beats Trump 50 percent to 38 percent. A 12-point lead looks strong … until you see Biden had a similar lead against Trump in the October 2015 Fox News Poll. Favorability rating? Biden is currently at 50 percent. Yet, it was 56 percent in 2016, 2017 and 2018.

While Biden may seem like a relatively steady frontrunner, when you look under the hood it becomes clear that one group of voters is keeping Biden in first place: African Americans.

In the latest Fox News Poll a staggering 84 percent of African Americans support Biden. Furthermore, 71 percent of nonwhite women support him. The good news for Biden is that African American voters are keeping his support at 50 percent. The bad news? If African Americans change their minds, then the bottom falls out for the former vice president.

In the latest Fox News Poll a staggering 84 percent of African Americans support Biden. If they change their minds, then the bottom falls out for the former vice president.

Biden's campaign is based on the “electability” argument. Democrats badly want to beat Trump and will back anyone who can do it. Today, that candidate is Joe Biden. The problem for Biden is the first two primary contests, Iowa and New Hampshire, have very few African American voters. It is not until South Carolina, the third contest, that African American are a sizable voting block.

If Biden loses either Iowa or New Hampshire, or both, then he may not make it to South Carolina. One or two losses in early February would pierce his argument of electability, costing him the support African American voters ... and the nomination. For example, if Warren won in Iowa and New Hampshire, she could run the table and win the nomination with African American support moving to her.

That scenario may explain why Biden was in Iowa and New Hampshire over the last five days rather than at the Democratic National Committee meeting in San Francisco, where virtually every other presidential candidate appeared. Biden knows he has to win the first two contests, or at least one, to be the nominee.

In the latest Des Moines Register poll conducted in June, the gold standard for Iowa polling, Biden was leading with 24 percent of caucus-goers. Sanders, Warren and Pete Buttigieg were in a dead heat for second with, respectively, 16, 15 and 14 percent. But Warren leads in the second choice and under active consideration categories, key indicators of support in the caucus system. So if Biden, or any other candidate, faltered, then Warren would be the likely beneficiary. In fact, many believe the Massachusetts senator is in an excellent position to capitalize on such a scenario because she has the best organization in Iowa.

In New Hampshire, an August poll conducted by Suffolk University has Biden in the lead with 21 percent, followed by Sanders at 17 percent and Warren with 14 percent. The margin over Sanders and Warren is hardly a comfortable place for Biden. Of course, New Hampshire is also a must-win for Sanders. He won that state's primary by 22 points over Hillary Clinton in 2016, but eventually lost the nomination to her.

If Sanders loses New Hampshire in 2020 it is virtually impossible for him to win the nomination. Once again, Warren leads the second-choice category at 21 percent, and 58 percent of voters said they could change their mind before the Feb. 11 contest.

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In Iowa and New Hampshire, Biden is looking over his shoulder at Warren.

In South Carolina, he is African Americans' insurance policy and they are his.

And that means Biden is the Democrats’ insurance policy too … for now.

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