  We examine the effects of introducing a political outsider to the nomination
process leading to an election. To this end, we develop a sequential game where
politicians -- insiders and outsiders -- make a platform offer to a party, and
parties in turn decide which offer to accept; this process conforms the voting
ballot. Embedded in the evaluation of a party-candidate match is partisan
affect, a variable comprising the attitudes of voters towards the party.
Partisan affect may bias the electorate's appraisal of a match in a positive or
negative way. We characterize the conditions that lead to the nomination of an
outsider and determine whether her introduction as a potential candidate has
any effect on the winning policy and on the welfare of voters. We find that the
victory of an outsider generally leads to policy polarization, and that
partisan affect has a more significant effect on welfare than ideology
extremism.
