Twitter Is a Critical Tool in Republican Campaigns Mitt Romney greeted supporters in Orlando, Florida on Friday. Top aides say they watch Mr. Romney's events with a Twitter stream open on their computer. When Newt Gingrich said in a recent debate that he was a man of "grandiose" ideas, Mitt Romney's campaign pounced. It sent mocking Twitter messages with a hashtag, "#grandiosenewt," encouraging voters to add their own examples of occasions when they felt Mr. Gingrich had been "grandiose." Within minutes, the hashtag was trending on Twitter. Reporters picked up on it, sending out their own Twitter posts and writing their own articles. The result: for at least one news cycle, the Romney campaign had stamped a virtual "grandiose" on Mr. Gingrich's forehead. If the 2008 presidential race embraced a 24/7 news cycle, four years later politicos are finding themselves in the middle of an election most starkly defined by Twitter, complete with 24-second news cycles and pithy bursts. With 100 million active users, more than 10 times as many as in the 2008 election, Twitter has emerged as a critical tool for political campaigns, allowing them to reach voters, gather data and respond to charges immediately. But like most new media tools, it also carries danger for the campaigns. It can quickly define the political debate, whether candidates like it or not, and a single 140-character missive can turn into a nightmare. "Twitter has changed the whole way that politics works," said Teddy Goff, the digital director of President Obama's re-election campaign. Not just the press element, but the organizing element and the fund-raising element and the relationship building that all campaigns try to do. Perhaps no Republican campaign monitors Twitter more closely than Mr. Romney's operation, which believes that it can ferret out bias among reporters by analyzing their posts. Their war room compiles all the Twitter messages from the press corps at every event and e-mails them to the campaign staff. "Twitter is the ultimate real-time engagement mechanism, so it's moved everything to a much faster speed," said Zac Moffatt, the digital director for the Romney campaign. You have no choice but to be actively engaging it at all times. Mr. Romney's aides say they can get a sense of where a story is headed before it is published simply by reading reporters" Twitter messages. If reporters have flagged a particular incident on Twitter - for instance, the woman who stood up at South Carolina event and asked Mr. Romney, a Mormon, if he believed "in the divine saving grace of Jesus Christ" - Mr. Romney's aides might pull him aside before a press conference and warn him that the topic is likely to come up. "It's a leading indicator of what people are thinking about," Mr. Moffat said. "It's almost like an early warning signal: "This is what someone's thinking." " The campaign will push back on posts that it thinks are incorrect or unfair, and nearly every reporter who covers Mr. Romney has received a Twitter-inspired lecture, ranging from a simple "not cool" to something angrier. This reporter is no exception. The Romney campaign is not the only one to use Twitter as a real-time news tracker. Ben LaBolt, a spokesman for Mr. Obama's re-election campaign, said Twitter allowed the team to see what was resonating with both voters and reporters. "If it's headed in a way you think will be helpful, you can fan the flames," Mr. LaBolt said. "Or you can reach out to people to say, "Oh, that's not what we really meant." " "You catch problems earlier," Mr. LaBolt added, "but things haven't gone through a filter, so you're almost playing Whac-a-Mole to shoot things down." With Twitter, rapid response has an even bigger role, with campaigns needing creative ways - video links, clever hashtags, pithy quips - to push their message, hoping to attract the attention of reporters and supporters. R. C. Hammond, a spokesman for Mr. Gingrich, explained: "There's a bunch of Mountain Dew-drinking college kids that keep an eye on it all the time." Adam Sharp, who manages government and politics for Twitter, said the site provided "a scalable approach to retail politics," giving voters intimate, one-one-one interaction with politicians.