Democrats can thank Missouri Sen. Claire McCaskill for keeping Twitter bipartisan. That's because she is the only Democrat to break into two key categories: the top five "most followed" lawmakers and the top five who post the most "tweets per day." Both of those categories are controlled by Republicans. McCaskill has more than 39,200 followers. But she tweets under three times a day, less than half of what the Senate Republican Conference posts. One reason for McCaskill's popularity is that she tweets on policy and her family goings-on, as in this recent post: "My husband thinks I tweet about what I had for breakfast, so in honor of him, made breakfast pizza for family on wonderful Big Green Egg grill."