COSTELLO: The balance of power over which party controls the House and Senate could shift. Republicans have the House now but would love to take over the Senate. Democrats control the Senate and, of course, would love to take control of the House. But does either side have a chance for a political gain of power? Let's ask CNN's senior congressional correspondent Dana Bash. She's in Washington. Explain to us how this power could shift.</s>DANA BASH, CNN SENIOR CONGRESSIONAL CORRESPONDENT: Well, Carol, let's start with where the Senate stands right now. Republicans have 47 seats. Democrats, if you add the two independents who caucus with them, have 53. Republicans need a net gain of four seats to get a clear-cut 51-seat majority. Now I want to show you a map of the universe of competitive races. There are a lot -- look at that. Over a dozen where both parties have been spending heavily and candidates are fighting hard. The problem, Carol, is that Republicans aren't just playing offense. They're playing defense on many of their seats.</s>COSTELLO: And that is a problem for Republicans. As you just said, they're not playing offense to take the Senate. They're playing defense. What does this mean?</s>BASH: Well, you know, there are five endangered Republicans seats. I want to show our viewers the map again but just showing those red seats. Look up in New England there, sources in the Republican Party tell us that they're not just endangered, that they believe that they're probably going to lose. And we're talking about Massachusetts, Senator Scott Brown. The polls there now are neck and neck. But Republicans</s>COSTELLO: Yes, we're all in a lot of misery like that together, especially if you live in those swing states or states with really competitive senate and congressional races. Thanks so much, Dana Bash, reporting live for us. "Talk Back" question for you today: "Defining moment, what was it in 2012?" We'll be right back.
Fighting to Control the Senate