For decades, campaign managers and spin masters have controlled the campaign messages blasting across the airwaves.

They used one focus group after another to determine which words to say and which images to use. Only then would a radio spot or television commercial make it off the drawing board and into the election campaign.

All that may be changing.

On March 5, an anonymous visitor to the popular video-sharing site YouTube uploaded a video attacking Sen. Hillary Clinton, D-N.Y., and promoting the candidacy of Sen. Barack Obama, D-Ill.

It's a very well-made ad. A remake of the 1984 Apple commercial that aired during the Super Bowl that year, the ad replaces the Big Brother image on the large screen with Clinton and turns the hammer-throwing athlete into an Obama T-shirt-wearing revolutionary.

The ad ends with a rainbow-colored O with an apple stem popping out the top and the address of the official Barack Obama Web site.

After bouncing around the Internet for a couple of weeks, it caught steam this weekend and now is the talk of the town — maybe not on Main Street USA, but it sure has the political class buzzing.

It's a creative ad, and from all the talk on television and radio that has developed in the last few days, it has obviously been effective.

But is it changing the political world as we know it? If you listen to the media pundits and the professional campaign operatives, the answer is a resounding yes.

The very fact that a creative and enterprising individual can create a compelling message that draws such a picture of two candidates and their contrasting images is a sign of where political campaigning is heading.

Ads and campaign materials created and distributed by entities not affiliated with the actual campaigns is nothing new — it's been happening since the dawn of politics.

In past years, independent groups have distributed outrageous fliers with devastating half-truths; political advocacy groups have bought up air time to broadcast negative ads for decades.

Not much could be done about the anonymous fliers, but McCain/Feingold and its restrictions on free speech and issue advocacy groups, like the Christian Coalition and the Sierra Club, have tried to stop independent expenditures from having their desired effect too close to the election. Congress in essence tried to create an incumbency-protection law.

That protection is quickly coming to an end. In the past, money was an insurmountable barrier on the average American to having an influence on elections but with the advent of the Internet, YouTube and viral Internet campaigns, any individual with access to a computer, creativity and limited technical skills can create a devastating message. Only the creativity and effectiveness of the message can limit its ability to spread like a wildfire.

The Hillary 1984 ad isn't alone. A quick search of the Internet and YouTube returns dozens of attack ads against nearly all the announced candidates for president.

In the 2006 election, several incumbents owe their defeat to an ill-advised comment caught on video tape and spread across the Web. It isn't a new phenomenon for campaigns to employ trackers. Operatives are routinely dispatched to follow the opposing candidate in hopes of capturing an inopportune moment on videotape.

What is new is that much more of the footage is being saved from a death on the cutting room floor and is now being posted on the Internet. The community of activists and citizens takes over from there. The results can be devastating. Just ask former Virginia Sen. George Allen, who had his "macacca" moment during the campaign and never recovered.

The Hillary 1984 ad isn't something new and certainly not a deathblow to her campaign, but the reaction of both the Obama and Clinton campaigns is telling. Both campaigns were pressed to comment on the new ad and neither campaign could muster better than a "We're aware of the ad. No comment."

The Obama campaign was also forced to deny it had anything to do with the ad.

Presidential campaigns are all about message control. Every successful campaign points to — as a key part of its success — the ability to stay on message no matter what the distractions.

The Internet blows that strategy out of the water.

Clinton and Obama can give all the speeches they wish about health care, Iraq and "uniting not dividing," but all anyone is talking about today is the Obama vs. Big Brother Hillary ad.

In one election cycle, young voters have gone from a demographic courted with rock concerts and campus rallies to political operatives with just as much influence on the national debate as the big boys in Washington, D.C.

Presidential politics just got a whole lot more interesting for the rest of the country.

Stay tuned.