Just adding to it, these sites could be really effective to rank well for certain negatives about the candidate and the opponent.

Say, the candidate was involved in a campaign finance scandal that was misreported and the campaign wants to ensure that voters know the truth. Start a website: http://www.janedoecampaignfinancescandal.com. Particularly if it’s an exact match domain it should rank highly quickly and be able to help correct the record for any voters interested in learning more.

On the other hand, you could use this same technique to rank highly on search terms for the opponent. What if your opponent has a view out of step with the district on guns. Get the domain http://www.johndoeonguns.com and explain where the opponent stands ranking highly in the SERPs.