By the Numbers: Half of the Senators Who Voted for Obamacare Will be Gone in 2015

Louisiana Republican Bill Cassidy's double-digit ousting of Democratic Senator Mary Landrieu on Saturday was, in the words of the senator-elect, an "exclamation mark" on a 2014 election that saw the Republicans win control of the Senate. With Landrieu's departure, only half of the Senators who voted to pass the Affordable Care Act will still be in office in 2015, when the new members are sworn in.

Cassidy's 56 percent to 44 percent win over Landrieu, in the last Senate race of the 2014 cycle, means that the Republicans will control 54 seats in the 100-member Senate beginning in January. That's a nice cushion for the party as it prepares to defend its hold on power in 2016, a presidential election year when Republicans will be the incumbent party in 24 of the 34 Senate elections.