The latest Joe Biden speculation basically falls into two categories: He’s leaning toward a presidential bid (unless he isn’t), and he’s a potentially formidable candidate (unless he isn’t). Truth is, nobody really knows. And that includes Joe, who at most has another month — until the run-up to the first Democratic debate on Oct. 13 — to make up his mind.

It’ll probably depend on whether he feels the tingle.

According to the late Richard Ben Cramer - author of the seminal political tome “What It Takes” and unsurpassed Biden chronicler, Joe trusted his instincts. When he didn’t feel the time was right to make a big move, he’d tell his aides, “I can’t feel the tingle.”

Supposedly, he sees a late bid as potentially tingleworthy, because Hillary’s email baggage has created an opening. And lest we forget, Biden got his start in national politics as a ballsy gambler. In 1972, at age 29, he was a unknown newbie who challenged — and defeated — a two-term Republican senator named Cale Boggs. As Cramer wrote in his book, “Biden was at three percent in the polls when he rented the best and biggest ballroom in the state for his ‘victory celebration.’”

But we’re not talking Delaware here. A decent presidential bid costs roughly half a billion bucks. Biden hasn’t raised a cent or hired any staff; by contrast, the Clinton machine is still prodigious.

More importantly, at a time when grassroots liberal voters are ticked off at Wall Street and the financial industry, Biden would have to defend his long cozy friendship with the banks and credit card companies. And at a time when Black Lives Matter activists are highlighting racial disparities in the criminal justice system, Biden would have to defend his key senatorial sponsorship of the 1994 federal crime law that has exacerbated those racial disparities.

Without populist liberals and African Americans, he wouldn’t have a prayer of winning the nomination.

Imagine what Hillary would do with this: In 2005, Sen. Biden serviced the banks and credit card companies by supporting a bill that made it harder for tapped-out consumers to file for bankruptcy. The bill became law with George W. Bush’s signature. Biden had voted for a similar bill in 2001. And, coincidentally or not, his son Hunter earned consulting fees from a major banking company, MBNA Corp., during the same period (2001 to 2005) when these bankruptcy bills were in the hopper.

The 1994 crime law would be a bigger problem. Biden was a key player, and has often boasted about it. In Time magazine last year, he referred to himself as “the guy who did the crime bill.” In an essay on crime that he wrote earlier this year, he referred to the law as the “1994 Biden Crime Bill.” Known formally as the Violent Crime Control and Law Enforcement Act, it established mandatory minimum sentences for drug offenses, incentivized the states to lengthen other sentences, provided funding for lots of new prisons, and created a three-strike provision that mandated life sentences for violent felons with two or more prior convictions.

This was smart politics at the time, but in the Democratic electorate of 2015, it looks like bad politics. The Clintons have already distanced themselves from the law. Bill signed it, but last month he told the NAACP, “I signed a bill that made the (incarceration) problem worse. And I want to admit it.” And Hillary moved left on the issue back in April, when she said it was time to end “the era of mass incarceration.”

All of which prompts me to quote a passage from Richard Ben Cramer’s book. This is an anecdote about young “Joey” Biden:

“Joey was always quick, with a grace born of self-possession....Once Joey set his mind, it was like he didn’t think at all - he just did. That’s why you didn’t want to fight him. Most guys who got into a fight, they’d square off, there’d be a minute or two of circling around, while they jockeyed for position. Joey didn’t do that. He decided to fight - BANGO, he’d punch the guy in the face...So Joey got into fights, and BANG - it was over quick. What he was, was tough from the neck up. He knew what he wanted to do and he did it.”

But does he have enough fight left in his tank to take on the House of Clinton?

Dick Polman is the national political columnist at NewsWorks/WHYY in Philadelphia (newsworks.org/polman) and a “Writer in Residence” at the University of Philadelphia. Email him at dickpolman7@gmail.com.