

Sen. Bernie Sanders (I-Vermont) laughs during a 2011 visit to Afghanistan. (S.K. Vemmer/Department of State. Used under a Creative Commons license)

Last week we established that Sen. John McCain (R-Ariz.) is Congress's reigning king of Twitter, with nearly 1.9 million followers. But Rep. Paul Ryan (R-Wisc.) is far and away the leader when it comes to Facebook: nearly 5 million people have 'liked' Ryan on Facebook. McCain is a distant second with 880,000 likes, followed by Sens. Ted Cruz, Rand Paul and Rep. Michelle Bachmann to round out the top five.

Republicans may dominate the upper echelons of Facebook friendom, but that doesn't tell the whole story. Another helpful metric is Facebook's "people talking about this," which tracks the number of times people have commented on or shared a post from a Congress member's Facebook page, or mentioned one in their own posts. On this measure, there's more party parity at the top.

Vermont's Sen. Bernie Sanders (I) has had over 288,000 people talking about him on Facebook in the past seven days, putting him at the top of this list. Cruz (R-Texas) is a close second with 267,000, while Sen. Cory Booker (D-N.J.) comes in third at 259,000.

Overall, while congressional Republicans seem to be more proficient at Twitter than their Democratic counterparts, when it comes to Facebook the results are more mixed. Republicans are slightly more well-liked on Facebook than Democrats - the median Republican officeholder has 6,977 likes, while the median Democrat 6,601.

Republicans lead on likes in the house, with 6,314 likes to Democrats 5,468. But the reverse holds true in the Senate, where Democrats have a median 17,176 likes compared to the Republicans' 13,196.

On the 'talking about' measure, the parties are dead-even - a median of 402 for each party in Congress. That split holds true in the House, with both parties at 361, but the Democrats do hold an edge in the Senate, at 740 to the Republicans' 517.

Taking all of this into consideration with last week's Twitter data, a number of key themes emerge:

The power of a national ticket

McCain and Ryan are the national leaders on several measures of Facebook and Twitter influence. This suggests that they've been capitalizing on and expanding the social media following they built during their respective White House runs in 2008 and 2012, respectively. In the past, members of failed tickets typically laid low for a few years after their defeat - see Al Gore in 2000, and John Kerry in 2004. But now that social media makes it incredibly easy and inexpensive to stay in touch with voters, politicians may no longer see any reason to retreat from the limelight to tend to their beards.

The power of a national social media presence

Social media may also prove to be a testing ground for 2016 contenders. A populist politician with enough social media savvy - particularly one who stands outside the usual party power structures - can give herself a huge edge going into national elections. Sanders is illustrative here. Democratic leaders are probably already a little nervous about a proudly Socialist senator hinting at 2016 ambitions. But they're probably made even more nervous by the fact that he has one of the largest and most enthusiastic social media followings out there. Imagine what Howard Dean could have done in 2004, had Twitter been around.

A large following isn't necessarily an engaged following

We tend to fixate on follower or 'like' counts because they're easy to track and easy to understand. But while these numbers are a necessary measure of social media influence, they're not sufficient. Having a large follower base doesn't do you much good unless they're also actively engaged. A good analogy would be voter registration and turnout: while its important to register voters, getting them to turn out at the polls is what wins elections.

Ryan and Sanders provide a useful comparison here. Ryan has more than 10 times as many Facebook likes as Sanders. But Sanders has an astonishing nearly 30 times as many people talking about him on Facebook right now. Sanders's audience is smaller, but it seems much more highly energized than Ryan's. This social media energy might translate into real-world action during an election.