Joe Biden has many strengths as a presidential candidate: experience, policy smarts, respect for the rule of law, an ability to do something more than watch cable news. Even a Sleepy Joe is a significant upgrade on a Dumbass Donald.

But what Biden doesn’t possess, no matter how many times lazy reporters and pundits say it, is a steel-like grip on the rust belt states that could decide the general election. No matter what you think of his politics or personality, the electability debate is – as the candidate might say himself – a bunch of malarkey.

Yes, Biden was born in Scranton, Pennsylvania, and his family stories about his father’s economic hardship are powerful and endearing. Yes, his Finnegan relatives in Scranton voted for Trump and may give him some insights into how to win such voters back.

But Team Biden should draw some profound lessons from the last time their candidate ran a presidential campaign, all of 12 years ago. Biden may be the instant frontrunner in national polls this time around, but his single-digit lead is trailing the double-digit margins that Hillary Clinton enjoyed at the same time in 2007.

Even in Pennsylvania, where Biden holds a double-digit lead over Bernie Sanders today, he pales in comparison to Clinton’s 20-point and even 30-point distance ahead of Barack Obama in 2007.

Those poll leads evaporated nationally when Obama won the Iowa caucuses. Even in Pennsylvania, Clinton’s commanding position collapsed as Obama started to win more and more primaries. Frontrunner status and polling leads are delusional foundations for a presidential campaign.

As their poll leads were melting away, the Clinton campaign and the national media extensively litigated the electability debate through the course of 2008. In fact, the long Pennsylvania primary of April 2008 was the time and place where every possible angle was explored.

Obama couldn’t connect with blue-collar votes because he was so intellectual. He couldn’t connect with the party machine because he was such an upstart. He couldn’t connect with white voters because he was so black. He couldn’t connect with black voters because he was so white.

Hell, he couldn’t even get a respectable score at the bowling alley. What a loser.

If all that coverage sounds far-fetched, well, it was, and nobody but the Obama campaign seemed to mind.

In any case, they had other problems. One was that the candidate appeared to dismiss small town voters by suggesting they were embittered by job losses, and were clinging to God, guns and racism as a result. The other was his former pastor, Jeremiah Wright, whose fiery sermons weren’t exactly an appeal to white Pennsylvania voters. It was easy to find such voters saying they didn’t think much of that Obama guy.

Sure enough, Clinton won the Pennsylvania primary by 9 points and everyone could feel good about the electability coverage. But it was still deeply wrong. Obama went on to win the next primary in North Carolina and only narrowly lost in Indiana.

The whole set of sweeping assumptions underlying the white working-class voter theory should have been buried at that stage. But they weren’t, and they still stalk the political landscape like zombies.

If white working-class voters can only connect with candidates who share their white working-class experience, then how exactly did Obama win Pennsylvania by a 10-point margin in the general election in 2008? How on earth did he even win Indiana on the same night?

For those who want to argue that Obama’s success was all down to the financial crisis, you might want to remember that Obama won Pennsylvania again, four years later, by a 5-point margin.

This recent history does not mean that life is easy for candidates of color. If the Trump years have taught us anything, it is that overt racism can be a powerful driver of identity politics for a highly motivated minority of voters.

Demonizing and abusing immigrants has helped Donald Trump lock down his support among Republican voters. His language about a supposed invasion at the border has seeped into mainstream coverage, unchallenged, despite all the data that clearly shows that immigration is far from its historic highs.

But beyond Trump’s torch-wielding nativists, what basis is there for thinking that rust-belt voters need a white face in the White House?

There are some ugly and stupid assumptions masquerading as political analysis here. The first is that white working-class voters have different concerns from their African-American or Latino co-workers. As if they don’t share the same daily struggles over low wages, expensive healthcare, and poor schools.

The second assumption is worse: that white rust-belt voters are somehow more important or more representatively American than any other type of voter. Thus the endless stories about how Trump country views all of Trump’s troubles (spoiler alert: they don’t care).

The third assumption is that if Trump fears Biden’s ability to steal his voters, then there must be something real going on. As if Trump’s fears and sense of reality are in any way connected to anything beyond what’s currently airing on Fox News.

This isn’t an argument for ignoring the needs of white rust-belt voters, or writing them off as lost to all Democrats. That would also be stupid: Democrats need to peel away some of those voters to win.

But the assumption that such voters can only be won over by white candidates does not stack up to recent history. Clinton was supposed to have a lock on Pennsylvania compared to Obama, but he won the state twice in two general elections and she lost it.

Make no mistake: Biden is a formidable candidate in the Democratic primaries. His insights into how to appeal to traditional working voters – of all classes and colors – will fuel a heated debate with Sanders. They just won’t give him a lock on the rust belt.

Trump may or may not be so vulnerable that he has convinced every sentient, sane Democrat that they can beat him handily. The Trump of 2020 is not the same Trump of 2016 who promised rust belt voters that he would bring back manufacturing jobs and drain the swamp in Washington.

Biden himself likes to say – among many other pithy aphorisms – that we shouldn’t compare him to the almighty; that we should compare him to the alternative.

That is also true of every other Democratic candidate. Compared to the alternative, Joe from Scranton has no more advantage than Kamala from Oakland or Cory from Newark.

• Richard Wolffe is a columnist for the Guardian US. He is the author of Renegade: The Making of a President