Democrats are worriers. So it was probably inevitable that presumptive presidential nominee Joe Biden would face some buyers' remorse, despite his strong showing in the primaries and continuing lead over Donald Trump in head-to-head polls.

The anxiety isn't wholly lacking in justification. Since the coronavirus pandemic sent the country into lockdown in mid-March, Biden has been largely out of sight, holed up in his Wilmington, Delaware, home. He's done interviews, read statements, delivered modest policy speeches, and recorded podcasts from his basement. Reviews of these decidedly low-tech events have been polite to awful. On Memorial Day, he ventured out of his house for the first time in over two months, wearing a mask.

The contrast with President Trump is stark. For weeks Trump placed himself at the center of the pandemic response, presiding over lengthy press briefings, tweeting constantly, and refusing to wear a mask in public as he urges state governments, businesses, and churches to begin reopening.

This has led many to fret that Biden has been left looking weak and marginal at a time of national crisis. Shouldn't he be doing more to place himself at the center of the political action?

The answer is no. With another nominee, this might not be the case. But with Biden it is.

Biden benefits by staying in the background. That's because his strengths as a candidate are rooted in his past: his nearly half-century of relating to voters on the stump; his decades of service in the Senate; his eight years as Barack Obama's vice president. The result is a warm glow of positive associations based on mostly cheery memories.

Nothing Biden says or does now is likely to add to this stockpile of affirmative feeling. On the contrary, the risk of him spending it down is high. Biden's longstanding proneness to verbal gaffes has curdled in recent years into frequent incoherence when he speaks without a script, and especially when he's confronted with tough questions. The latest example took place just last week, when Biden appeared on a prominent African American radio program to discuss his campaign's outreach to black voters. When the host Charlamagne Tha God expressed displeasure that the candidate had run out of time and requested he return at some point in the future to continue the conversation, Biden responded, "If you have a problem figuring out whether you're for me or Trump, then you ain't black." The campaign and candidate spent the next few days scrambling to clean up the resulting mess.

Biden prevailed in the primaries despite this weakness, not because of it. This could well become an issue in the fall, when Trump and his surrogates will be gunning for him on a daily basis. Why put the presumptive nominee in the line of fire sooner than he needs to be if it could end up weakening him? Far better for Biden to remain out of sight as long as possible.

But there's something bigger going on here as well.

The Democratic Party is ideologically broad, stretching from Vermont Sen. Bernie Sanders on the left to billionaire Michael Bloomberg on the right. The party is also demographically diverse, encompassing blacks, Latinos, Asians, urban white progressives, Midwestern working-class whites who are economically liberal but culturally conservative, the LGBTQ coalition, and more. Biden appealed to a much bigger share of the party than any other candidate in the primaries. That made him a formidable contender for the nomination and makes him a strong candidate to go up against Trump in November.

But that doesn't mean Biden succeeds in being the perfect Democrat — with perfection defined as a candidate who manages to achieve maximal appeal to the members of the party's highly differentiated electoral coalition. Obama, a once-in-a-generation political talent, may have come as close as possible to being such a perfect candidate during his 2008 presidential campaign. Today, the only person who approaches that level of support is imaginary — the "generic Democrat" pollsters ask voters about in their surveys.

According to recent polls of the generic congressional vote, a generic Democrat prevails over a generic Republican by an average of 8 percentage points. With Biden currently beating Trump by 5.5 points, that puts an imagined congressional Democrat 2.5 points ahead of Biden.

A Biden who largely stays out of sight, avoiding embarrassing gaffes and steering clear of providing additional evidence of cognitive wear-and-tear, is a Biden who comes closer to resembling this imagined generic Democrat. The more he does the opposite, appearing frail and sounding flummoxed on a daily basis, the more his support is likely to sink, with imagined perfection slowly replaced in the minds of voters by all-too-real defects.

How far would Biden's support be likely to fall in such a scenario? There's no way to know for sure. But in thinking through these electoral dynamics, it's important to note that, for all of Trump's electoral weaknesses (including an approval rating 10 points under water), the president's position in head-to-head polling against Biden (42.9 percent) beats the generic Republican showing of 39.7 percent by 3.2 points. This would seem to imply that Trump benefits (at least among members of his own party) by his omnipresence in the media and the outrageousness of his behavior.

Put it all together and we're left with ample reason to think that Biden should keep mostly sitting on the sidelines until after the political conventions this summer, when the general election campaign traditionally begins in earnest. At that point, the Biden campaign will need to decide precisely how, and how much, to use the candidate on the stump. This will also be the time for the campaign to think about whether keeping the Democratic nominee out of the spotlight actually delivers a positive message about the glut of odious political news in the Trump era — and the promise of a welcome relief from politics during a Biden administration.

This could be one of those times when the best way to win the game is barely to play at all.