Political campaigns used to rely on speeches, rallies, and newspapers to reach and motivate voters. Then radio and television made it possible to reach everyone quickly and simultaneously. Today, campaigns can spread their messages instantly - and, interactively - through the Internet's so-called "social media".

The Internet's role in political campaigning has grown hugely over the past 20 years. It's used to spread the candidates' messages, to raise money, and to motivate voters to get actively involved.

Transformative communication

When Democratic Party presidential candidate Barack Obama ran in 2008, his team used the Internet to a degree never seen before - and with significant effect, says political communications strategist Peter Fenn.

"First of all, if you look at the numbers on this, it's absolutely incredible. He had 4 million donors to his campaign, which is about one in every 17 people who voted for him gave him money," said Fenn. "That had never happened in American politics. Second thing is [that] you had about 16 million email addresses that he had of folks."

In the 2012 presidential election, both major candidates - the incumbent president, Obama, and his Republican challenger, Mitt Romney, are using the Internet - including social media such as Facebook and Twitter - massively, and strategically.

And, each form has a role to play in message delivery, says the Romney campaign's Digital Media Director, Zac Moffat.

"The way that I would think about it is Twitter is kind of the ultimate real-time engagement tool. Twitter is the conversations occurring in real time," said Moffat. "I would think of Facebook as happening 'that night' - it's almost like currently the event has occurred, and people are reflecting upon it. And then, Google kicks in the next day, and they are able to kind of put structure to all of that madness, and is able to say 'OK, this is how people talked about it.'"

Interactive, responsive body politic

Social media also enable voters to respond to candidate mis-statements and awkward situations.

"It's hard to know just how well the word will turn out. There are a few things that are disconcerting."

With them spread like wild fire across the Internet, political newspaper correspondent Tony Romm: "There is a piece of information... and it begins to bounce around, essentially. It's shared, it's repeated. It reverberates. We see that when things like gaps. Somebody says something on twitter and that begins to explode in popularity where people are retwitting it and creating hashed hats around it. We see the same thing with Facebook, when a user shares a news story about something a candidate has done. And then, that begins to explode, eventually winding up in major newspapers, making major headlines across the country. So, it has a huge effect."

Internet political strategists say the goal with social media is to collect data from voters in order to personalize the campaign - to make the candidate not only familiar, but also to be seen as a friend who knows and understands the problems voters face and want solved. That, analysts say, is the 'retail politics' of today - and tomorrow.

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（来源：VOA 编辑：实习生朱眉霖）