WASHINGTON – A bruising political battle like the one between Gov. Rick Perry and Sen. Kay Bailey Hutchison usually means a slew of tough television ads. But for now, the candidates are saving their barbs for the Web.

Perry online ads depict Hutchison as a free-wheeling liberal spender in Washington, while Hutchison features Perry aiding the community-activist group ACORN, a favorite GOP target.

The ads appear mostly on conservative Web sites, such as the Drudge Report, and are bent on swaying the party faithful. They are colorful, sardonic and often meant to demean the opponent's fidelity to the GOP. But media experts warn that what may work in the primary could hurt the winner come the general election.

"You have two candidates that are very well known, so it's not about name recognition; it's about reframing the candidates and raising doubts if you can really trust the candidate who you might support," said Amy Jasperson, a political communications professor at the University of Texas at San Antonio.

A campy Perry ad depicts an unflattering Hutchison portrait atop one old-fashioned locomotive crashing into another, beneath the quote "like watching a train wreck." It has similar artwork to an ad under the headline "Delivering record bailouts, pork & debt ... since 1993."

One of Hutchison's ads meant to make voters doubtful of Perry's sensibilities calls him out for signing ACORN-backed legislation in 2005. It's a stark black-and-white box with the final thought: "Click here to help elect a governor who won't stand with ACORN."

Hutchison also features colorful ads with cartoons and maps about issues such as the Trans-Texas Corridor and property rights.

Typically, voter turnout is low in primary elections, even with high-profile players. Those who do vote are interested and engaged in politics.

Jasperson said direct mail, broadcast and print ads will ramp up when it's time to pull in a wider voting crowd, but online ads better serve the candidates' purpose at the moment: to jab the opponent in front of onlookers who are most likely to turn out on March 2.

"They can get a little more brave online ... in terms of the nature of the attack," Jasperson added. Ads for other media are typically more toned-down.

At the moment, the primary is the main event. But Jasperson said the candidates must be careful, because whoever wins must live with what they say during the primary, which could be troublesome for a campaign attempting to appeal to an increasingly centrist state.

But winning the primary must come first. Perry's goal through his online ads should be maintaining his hold on the base, said Harvey Tucker, a political science professor at Texas A&M University.

And Hutchison has two options, he said: Try to chip away at Perry's command of those voters, or attempt to spur higher voter turnout by courting more than the hard-core Republicans. The candidates' online ads are reflective of the strategies.

"They're not broadcasting, they're narrowcasting," Tucker said, adding that Hutchison should target staunch Republicans and "put doubt in their minds" about Perry.

Online ads can provide the targeted messages the two now need, whereas print and broadcast ads force candidates to blanket a wide swath of voters with one message, said John Brabender, a national political media consultant.

And Brabender said the focus on Internet advertising represents a profound shift.

"The Web used to be the condemned jail sentence of any poor ad," Brabender said, whereas now, candidates spend five times more money online than they did two years ago.