Marginal Revolution blog examines the difference between scholars and activists. I, in principle, agree with him that activists take an assumption and accept only the data that agrees with their assumption.
But not all activists have done that. Some activists became activists after being thoroughly effective scholars. However, that list is very tiny.
Not on that list are the proponents for Intelligent Design, abstinence-only sex education, or drilling in ANWAR. Nor are the Dworkin feminists, Bly mannists, or Michael Moore style documentarians that infect our society. They can be entertaining, but they have no business try to claim status as scholars.