To Personalize or Depersonalize? When and How Politicians' Personalized Tweets Affect the Public's Reactions in the Journal of Communication (62 (2012) 932-949) describes an interesting empirical study on the subject done by Eun-Ju Lee and Soo Youn Oh in Sout Korea. They come to the conclusion that it simply depends on the groups of voters one is trying to reach.
Not much has been done to investigate how useful Twittering actually is for a politician's campaign. A study on the benefits of campaigning on social network sites in 2009 (by Utz, cited in Lee and Oh) found that people had a more positive attitude toward a political candidate when he responded to the them on his social networking page.
A number of politicians come to mind who came to be seen as more personable and down-to earth. Often they were also described as charismatic. Bill Clinton and Tony Blair come to mind, but also Ronald Reagan who is thought to even have softened a financial crisis by going horseback riding after the stock market crash. This gesture told people that there was nothing to worry about.
People are more or less likely to align themselves and identify with political parties and groups. Identifying with a group means perceiving less individuality which is summarized in the rather complex sounding social identity model of deindividuation effects (SIDE). If the candidate as group leader sends out a personally sounding message to voters members of the group may be put off because they no longer feel as special by belonging to the group.On the other hand, someone belonging to another group may feel less discriminated when receiving a personal message from another group.
One important result of the study is that people highly affiliated with a part may even experience a negative emotion when they see highly personal campaign messages are being sent out. People with lower party affiliation or even another party affiliation felt more positively about the message. This leaves a campaigner with two options. Assume that people with high affiliation will not change their voting behavior, or discriminate who you send which message to. This may still sound academic, but the underlying logic sounds convincing. If you feel strongly about the party you belong to, especially because you also have a sense of belonging and maybe even exclusiveness because of your membership, how do you feel if the candidate begins spamming with personal messages. To be sure, this is an extreme case, but the basic concept holds true in communication theory and should at least be kept in mind by campaigners and voters alike.