Joe Biden was in Pittsburgh on Labor Day to give a few speeches and march in a parade to honor the nation's workers.

But of course, that boring sentence doesn't convey the Complete Biden Experience. This Vine, courtesy of CNN, does much more justice to Biden -- and suggests why he might present a problematic contrast to Hillary Clinton if he decides to run for president in 2016.

Yes, that's Biden running through the parade. (Sidebar: I love the woman in the sunglasses in front of Uncle Joe who sees him coming, whips around and veers out of his way.) What's clear from that eight seconds or so of video is that Biden LOVES this stuff. He, more than anyone since maybe Bill Clinton, loves the hail-fellow-well-met side of politics; the grip and grin that most politicians loathe is the sort of stuff Biden lives for.

Need more proof? Check out this picture from the parade:

Vice President  Biden, left, greets the crowd gathered along the streets as he walks in the annual Labor Day parade on Sept. 7 in Pittsburgh. Hearing chants of "run, Joe, run," Biden marched in Pittsburgh's annual Labor Day parade on Monday as speculation swirled about a potential late entry into the Democratic presidential campaign. (Keith Srakocic/AP)

Or this one:

Vice President  Biden shakes hands with a girl during the annual Allegheny County Labor Day Parade on  Sept. 7  in Pittsburgh. Biden has been subject of speculation about whether he will run for the U.S. presidency. (Jeff Swensen/Getty Images)

Or, heck, this one:

Vice President  Biden takes a selfie with a supporter during the annual Allegheny County Labor Day Parade on  Sept. 7  in Pittsburgh.  (Jeff Swensen/Getty Images)

The guy just eats this stuff up. And it's infectious. People smile, they laugh, they have a good time when they are around him.

Contrast that with the candidacy to date of Hillary Clinton. Lots of words come to mind when you think of how the former secretary of state has campaigned, but "fun" is not one of them. No matter what she says, it just doesn't look like she is having a very good time. (Her campaign, recognizing that fact, has pledged to make her more human in the coming months. Um, okay.)

Biden's energy and enthusiasm make Clinton's dourness stand out even more. And Biden isn't even a candidate yet.

I'm on record as being skeptical that there's enough space or time for Biden to carve a path to victory in this race. But man, could he make things uncomfortable for Clinton.