Is Joe Biden in tune with the times, or past his prime?

In Iowa, where the presidential primary season traditionally begins, a statewide poll has anointed Joe Biden as the Democratic front-runner, with 27 percent support. Another new poll says that Biden leads the Democratic race nationwide, with 28 percent support. Those stats seem impressive, considering the size of the likely Democratic field. So why does Biden continue to play Hamlet and hesitate within inches of the starting gate?

Because he’s been around long enough to know that early polling leads are often ephemeral. Two random examples tell the tale. In 1983, on the eve of a presidential race, the Democratic front-runner, leading nationally with 28 percent, was ex-astronaut and sitting senator John Glenn — who turned out to be a stiff on the stump. And in 2007, on the eve of another race, the Republican front-runner in the polls was future Trump toady Rudy Giuliani — who wound up spending $60 million and winning a grand total of one delegate.

Biden appears to be inching toward his third presidential bid — supposedly, he’s now “95 percent” certain to run; supposedly, he has signaled that intention to allies; supposedly, the big announcement is only a few weeks away — but it’s not hard to understand his hesitation. The early polls tend to measure name recognition, and everyone knows that “Uncle Joe” was Obama’s veep. The early polls do not measure what may well happen when a 76-year-old white guy tries to woo a party that’s being energized by young non-white progressives.

Perhaps it’s true, as evidenced in some surveys, that Democratic primary voters are so stoked about beating Trump that they’ll nominate a candidate who’s less than pure on their pet issues. If so, Biden has a shot. The conventional wisdom, which might actually be wise, is that Biden, with his hardscrabble Scranton heritage, can win back many of the working-class whites who defected to Trump in the pivotal Rustbelt. And the case can be made that the road to victory in 2020 will go through Pennsylvania, Michigan, and Wisconsin — all of which tilted red in ’16.

But Biden’s long season of tortured indecision (November 2017: “I haven’t decided to run, but I’ve decided I’m not going to decide not to run”) can be traced to his reasonable suspicion that time may have passed him by. He failed as a national candidate in 1988 and 2008 – indeed, he has never won a race on his own outside tiny Delaware — so why should he, or we, believe that he can succeed in an era when racial and #MeToo sensitivities are so acute?

As Biden tiptoes ever closer to a bid, his long track record in Washington is being systematically exposed. Perhaps it wouldn’t matter to black Democratic primary voters that Biden, as a young senator in the early 1970s, vocally opposed busing as a tool to integrate schools. Perhaps they wouldn’t care that, in 1975, he scoffed at integration with the kind of reasoning you might hear on Fox News: “What (busing) says is, ‘In order for your child with curly black hair, brown eyes, and dark skin to be able to learn anything, he needs to sit next to my blond, blue-eyed son.’ That’s racist!”

Perhaps black Democratic primary voters wouldn’t care that Biden, still a senator in 1994, authored what he proudly called “the Biden crime bill,” which triggered mass incarceration, disproportionately among African-Americans, and prompted one study to observe that “the United States imprisons a higher proportion of its population that any other developed country.” And perhaps they wouldn’t care that he still speaks fondly of the bipartisan days when he worked across the aisle with the likes of segregationist Jesse Helms.

Perhaps they truly wouldn’t care about any of that; perhaps Biden’s senatorial track record matters a lot less than his loyal tenure with Barack Obama. But we won’t actually know unless Biden is on the ballot.

And perhaps female Democratic primary voters wouldn’t care about Biden’s chairmanship of the Senate Judiciary Committee. Perhaps they’ll shrug off  the hearings that took place a long time ago — it’s been 28 years — when Anita Hill accused Clarence Thomas of sexual harassment. Biden refused to seat a panel of sexual-harassment experts, and he allowed Thomas to speak twice, before and after Hill. Perhaps female primary voters would ignore that history if and when Biden’s rivals resurrect it and drive it on social media. Perhaps they wouldn’t care that, in our hands-off-women era, Uncle Joe is notoriously hands on.

Perhaps they truly wouldn’t care about any of that, because Biden has also championed the Violence Against Women Act; and that Biden, as a politician, is sufficiently shrewd enough to support policies and candidates that honor the party’s female-driven energy. But we won’t actually know unless he’s on the ballot.

And would it matter to populist progressives that, as a senator from corporate-friendly Delaware, he used to champion the credit card industry, at the expense of consumers? Would it matter to grassroots Democrats that Biden inexplicably describes Mike Pence as “a decent guy”? (Democratic candidate Pete Buttigieg’s assessment of Pence is more responsive to the grassroots Democratic mood: “How could he allow himself to become the cheerleader of the porn star presidency? Is it that he stopped believing in Scripture when he started believing Donald Trump?”)

Last autumn, a former Biden campaign aide told me privately, “What I’m thinking is this: ‘Joe, you were always a bad candidate and now you’re too old and too white and too male.'” No wonder Biden has tarried so long near the launch pad. The last thing he wants is to crash to earth like John Glenn.