Vice President Biden's unprecedented planned visit to Tampa during the Republican National Convention there next week is causing a big stir and apparently surprising a lot of people.

But it probably shouldn't.

Biden's visit represents merely that latest ratcheting up in a behind-the-scenes campaign practice known as "bracketing."

And while this appears to be the first time someone with the stature of a sitting vice president has crashed such a major event for the opposing party, it's not that far removed from the campaign tactics and bracketing that have been a mainstay on the campaign trail in recent months and years.

In fact, it was just four years ago that the GOP's effort to assert itself at the Democratic convention was raising eyebrows. That effort, as it happened, included Mitt Romney and several other high-profile surrogates for Sen. John McCain's (R-Ariz.) campaign, including Rudy Giuliani and Tim Pawlenty, traveling to Denver.

"Mr. Romney’s Denver visit was further evidence of the Republicans’ decision to buck tradition this time around, by running a fairly full-scale opposition campaign during the Democrats’ convention," the New York Times wrote back in 2008.

Romney actually ventured into the convention venue itself -- the Pepsi Center in Denver -- which the Times billed as a "highly unusual move."

Both sides have used such tactics this year.

Romney's campaign has done plenty of this sort of thing, as The Post's Philip Rucker noted back in April. Romney has even held an event at a spot overlooking the site of the Democratic National Convention, Bank of America Stadium in Charlotte. Romney also went to Lorain, Ohio, just a day after President Obama spoke there in April, dispatched Sen. Rob Portman (R-Ohio) to Colorado during Obama's visit earlier this month, sent Louisiana Gov. Bobby Jindal and former Minnesota governor Tim Pawlenty to "welcome" Obama to Pittsburgh in July, and has dispatched a spokesman to several Obama campaign events.

Back on the night of the Iowa GOP caucuses,  Obama took part in a video teleconference with Democratic caucus-goers, even though he didn't have a competitive race. And similar to Romney's Charlotte event, the Obama campaign dispatched senior adviser David Axelrod to Boston earlier this year to give a press conference on Romney's governance of Massachusetts. (Axelrod, as it happens, was met by Romney supporters who bracketed him and successfully shouted him down, another example of evolving -- or perhaps devolving -- campaign tactics.)

Romney responded to criticism of the hecklers by noting the Obama protesters that have shown up at his events.

“At some point you say, you know what, sauce for the goose is sauce for the gander,” Romney said.

And it's not just the general election. That same Romney spokesman who has chased the Obama campaign followed GOP challenger Rick Santorum around during the Republican primary season. And let's not forget Texas Gov. Rick Perry's campaign announcement, which took place the same day as the Iowa straw poll (and was broadcast inside one of the tents in Ames.)

Some complained that Perry's spotlight-hogging was poor form and took away from the festivities in Ames. But it undoubtedly worked.

Despite Rep. Michele Bachmann's straw poll win, Perry was immediately bigger news, and he blunted any momentum that Bachmann -- who threatened to draw from the same supporters Perry sought -- might have gained from her win.

Biden is not going to overshadow the GOP convention, and his visit is likely to be merely one sideshow in an event full of sideshows. But in the age of 24-hour news, you simply cannot let your opponent monopolize the media in a locale or in a particular time period. And both campaigns have altered their tactics to reflect that fact.

"Totally fair game to counter-program, something both sides have been doing for years," said Democratic strategist Paul Begala. "Besides, it makes the whole thing more interesting -- like sending the bride's hot former boyfriend to a wedding."

The decision by the Obama campaign to use Biden in such a role may break new ground in this back-and-forth and cause heads to turn. But during campaign season, the vice president is really just the president's top campaign surrogate -- as Romney, Giuliani and Pawlenty were for Republicans in 2008 -- often playing the role of the proverbial "pitbull."

"There's 75 days left, and we're going to use each and every one of those days," said a senior Obama campaign official.

About the only difference between what Democrats are doing today and what Republicans did in 2008 is that Biden has a day job in the White House.

"You can seldom compete against the headliners with surrogates, but the vice president is different," said GOP consultant Ed Rollins. "Some of the 15,000 press might be interested in what he has to say."

That may be an important distinction for some, but in a campaign full of incidents that have gone beyond the pale and regularly tested (and passed) the limits of good taste, Democrats sending Biden to the opposing party's convention actually seems about right.