It’s not just Earthbound voters who are intensely following the U.S. presidential campaign: The race also is a hot topic in the virtual world of Second Life. John McCain supporters and Barack Obama supporters — more accurately, the personas they have created — meet regularly in Second Life, described on its Web site as “an online, 3-D virtual world imagined and created by its residents.” They watch the presidential debates together. They make T-shirts, banners and yard signs. They hold voter registration drives and rally on Capitol Hill.