How can there be such a phenomenon as electronic political activism? What's so active about clicking a mouse button when sending an e-mail or logging on to a Web site? But with $13 million and more than 650,000 volunteer hours pledged to Censure and Move On, a grass-roots Internet campaign against the impeachment trial of President Clinton, the realm of political activism now must bend its boundaries to include cyberspace. MoveOn.org, based in Berkeley, Calif., has been mobbed by more than 475,000 citizens who have signed the movement's one-sentence petition: "The Congress must immediately censure President Clinton and move on to pressing issues facing the country." Another petition, which is the proclamation of the organization's "We Will Act" volunteer campaign, was also sent to every senator and House member in Congress. It says: "In the 2000 election, I will work to elect candidates who courageously address key national issues and who reject the politics of division and personal destruction." MoveOn co-founder Joan Blades said, "We have sent a strong message that there are a lot of people out there who are unhappy with the impeachment trial." The money and volunteer hours pledged will be donated to congressional candidates in the 2000 elections who share the views of the MoveOn organization -- in effect, punishing those in office who have been in favor of continuing the impeachment process by directly supporting candidates who run against them in 2000. Blades has dubbed this the "We Will Remember" branch of the movement. This firestorm of political activism began Sept. 22 when Blades and her husband, Wes Boyd, set up a Web site (www.moveon.org) for $89.50 and told their friends about it. Within a week, 100,000 people had signed the petition. Now, more than 475,000 signers later, Blades said she has her hands full with "far and away the largest on-line petition" and one of the largest political action committees in the country. "We already have more money raised than the biggest political action committee of the last elections," Blades said. "We're blown away by this. We knew people were concerned, but we are amazed." Jonah Seiger, principal and co-founder of Mindshare Internet Campaigns, a Washington D.C.-based political consulting firm, said MoveOn is sailing uncharted waters. "The numbers that the MoveOn campaign is receiving are larger than anything else I have ever seen," he said. "A half million people in four months is very impressive and unprecedented." Since MoveOn chose not to directly collect the donations, the amount of money and time pledged that actually will be given will be incalculable until Election Day approaches in 2000. But Blades is hopeful. "I hope 100 percent of the pledges will come through," she said. "We've talked to some fund-raisers, and they said it's generally about 95 percent or better. . . . But say it is only like 50 percent, that is still a huge amount of money." Seiger said he'll be eagerly watching the final numbers. "In pledging, there's going to be some percentage that won't materialize," he said. "But they have an active group of participants in this case, and that suggests that people will be willing to follow up on their pledges." Blades said the impeachment issue has seemingly crossed party lines -- outside Congress, that is. About 60 percent of the movement's pledges are from Democrats, 30 percent from independents and 10 percent from Republicans, Blades said. "And that's still tens of thousands of Republicans," she added. All of MoveOn's trailblazing has occurred through what used to be known as "word of mouth." But as the inventive Blades said, it's more fitting to describe the trend in this case as "word of mouse."