Joe Biden, 76, has been getting heaps of attention for his verbal gaffes. Alas, voters should worry about a far bigger problem: It’s impossible to know what he stands for.

Yes, some of his slip-ups can be head-scratching. Democrats choose “truth over facts,” he said. Huh? The kids from the Parkland high school shooting — which happened after he left office — “came to see me when I was vice president.”

He lamented “the tragic events in Houston” and “Michigan” rather than El Paso, Texas, and Dayton, Ohio. He warned against giving President Trump “eight more years” and told backers to “go to Joe 30330,” instead of texting him. And that’s just recently.

Sometimes his flubs raise serious questions about what he thinks, as when he asserted that “poor kids” were as bright as “white kids,” though he quickly corrected himself (as, to his credit, he usually does).

His advisers insist it’s not his age but just “Joe being Joe.” That’s hardly consolation. Still, misspeaking isn’t the worst of sins.

The bigger trouble is that, even when he’s not mangling words, it can be hard to tell his true position — not just because he’s inarticulate but because some of what he says is just plain bizarre. And because he’s flip-flopped so furiously under pressure from his Democratic foes.

Initially, for instance, he insisted America is “in competition with China.” Yet in May, he discounted Beijing as a serious rival and blasted its critics: “China is going to eat our lunch? Come on, man … They’re not bad folks.” That was no verbal goof.

Then, when those comments drew fire, he switched back: “China poses a real challenge to the United States and in some ways a real threat,” he said.

For decades, he backed the Hyde Amendment, which bars public funding for abortions. Yet when fellow Dem wannabes called him on it, he caved: “I can’t justify leaving millions of women without access to the care they need,” he said.

He touts ObamaCare, which he helped to become law, but his new health plan, which includes a “public option,” would effectively gut it over time.

He apologized for backing the bipartisan 1994 crime bill. People convicted of drug crimes “should be going to rehabilitation,” not prison, he now says.

Democratic voters can rightly worry that he may switch back on his new positions or even stake out new ones if he gets the Democratic nomination or becomes president. Moderates or those on the right who liked the old Joe’s views better might fear that he won’t.