Schrage pointed to what he called a "disturbing" video posted by a YouTube user that featured the late son of presidential hopeful John Edwards. He said the company, after much contemplation, ultimately decided it was not in a position to remove it.

"We are redefining boundaries when it comes to the personal lives of candidates and their families," Schrage said in his conference keynote speech at George Washington University. "We all have to be more vigilant about protecting the truth."

As more and more candidates and voters use the Web as a soapbox, the public-relations chief acknowledged that the search giant is left in an awkward place. He said he believes that "self-policing" is the best way to prevent online mudslinging.

"We're not in the business of assessing truth or falsity," he said in response to an audience member's follow-up question. "That's not a path we want to take, or we think is appropriate, or our users would expect."

Schrage was also quick to point out the unprecedented democratizing benefits he believes the Web has brought to candidates and voters. He said the Internet has led to easier interaction between politicians and constituents, greater accountability for politicians who make missteps and a broader fundraising base.

Google hopes to promote that exchange by creating a special sales team to handle ad requests from political campaigns. It has also invited all of the 2008 presidential candidates to journey to the Googleplex to "talk tech and policy and maybe even grab lunch," Schrage said.

If the candidates agree to it, Google hopes to film some of the visit and put the videos they produce online, he added. YouTube recently launched a site called YouChoose '08 that provides an official platform for the presidential candidates to post videos.

Other concerns range from so-called Google bombing--that is, manipulating search rankings to render artificial results--to what Schrage deemed the very real possibility of political spyware planting itself on unsuspecting users' computers.

For the company that likes to say its mission is organizing the world's information, it will remain a challenge to give voters the information they need without overwhelming them, Schrage said.

"I defy anyone here to search for 'Hillary 2008' and read all the results without passing out," he quipped, adding: "not because of the content, mind you, but because of the volume."