Should researchers disclose their political interests in publications?
The researcher should probably disclose any bias she knows she has, though outside of potential biases due to funding of the research (think drug companies funding studies for their products), I don't think this is done much. Prominent public intellectuals usually wear their biases on their sleeves, so reviewers are often pretty aware of them. I'm not sure matters as much for less well known academics unless there's a worry that they were cooking the data.