Then-Sen. Joseph Biden is interviewed by TV journalists aboard the train from Wilmington on July 28, 2005.
(Melina Mara/The Washington Post)

Okay, he’s been vice president long enough that Joe Biden going off script isn’t a huge shocker. Many will never forget his honest answer about legalizing gay marriage in 2012 that caused an epic White House scramble to get President Obama on the same message.

So on Wednesday, when Biden — well known for his deep affinity for transportation issues, particularly his beloved Amtrak — criticized Congress over transportation spending, he again veered off the administration rails.

“Hell, Congress can’t even decide on a gas tax to keep the highway system going,” Biden said during remarks about the border crisis.

But wait! The Obama White House, since the very early days in 2009, has been adamant about one thing: They would not raise the $18.4 cents-per-gallon federal tax on gasoline to pay for highway investments. Taxes don’t make for good politics.

As the Loop wrote last month, we have a sneaking suspicion that Transportation Secretary Anthony Foxx may not be as opposed as his bosses. Just take a look at how former DOT secretary Ray LaHood changed his tune as soon as he was unshackled from the Cabinet. And it appears Biden would like to see Congress raise the tax, too. (The vice president’s office has not responded to our request for further clarity.)

The taxes on gasoline were last raised in 1993 during the Clinton administration, and before that by President “Read my lips: No new taxes” George H.W. Bush in 1990, and by President Ronald Reagan, who had also promised no tax increases, in 1982.

The money needed to repair and maintain, not even improve, the nation’s infrastructure far exceeds how much is brought in through the gas tax. Business groups and many members of Congress want to raise the tax now to bolster the Highway Trust Fund while other financing streams are debated. But underscoring the difficult politics of it, an AP-Gfk poll released this week found that only 14 percent of Americans support raising the tax by six cents, though 59 percent said the benefit of quality transportation outweighs the cost to taxpayers.

Will Biden’s “gaffe” send the White House into a tizzy like his gay marriage remarks? Unlikely. It’s an election year, after all.