Partisanship Elevates Extremism

Nate Silver, over at fivethirtyeight, has mentioned numerous times that, after holding a number of factors constant, more moderate candidates perform better than candidates with extreme positions.  The mechanism works in two parts.  First, moderates are more likely to win over a larger share of the ‘getable’ independents that genuinely sit in the middle and vote for democrats and republicans.

The second reason is a little less intuitive.  Extreme candidates on the right and left certainly motivate the wings of their party.  They bring, who would otherwise be unmotivated to vote, off the sidelines and into the political arena for their side.  However, there is evidence that extremists disproportionately motivate the other side’s voters.  So, while members on the extreme can motivate extra voters on their side, those numbers are swamped by the other side’s newly motivated voters.

In an age of weak parties and strong partisanship, does this still hold?  When any democratic nominee will be characterized by republicans (read: Trump) as an identity-politics wielding socialist, do these two factors actually hold?  Perhaps.  But there is a concern that Trump’s ability to (mis)characterize moderate contenders may actually dampen the both practical electability advantages moderates have over extremists within the democratic party. 

In a world where moderates and moderate independents refuse to cross party lines due to strong partisanship and one in which the political strategy of the day is to ramp up the extremes on both sides of the aisle, the argument and advantages for a moderate candidate seem to be non-existent.   When either side’s moderates won’t budge and the other side’s extreme is already motivated, we might as well pick the candidate that motivates the most people.  This person is often rather extreme.

Independents and moderate in both parties need to be willing to reward centrism and moderation—no matter the party.  Otherwise these voters risk rewarding the very types of politicians and policies they most dislike.