ROBERT SIEGEL, HOST:
Think everything's going to be the same on Capitol Hill this year? Well, think again. A new Congress that takes the oath tomorrow and the elections of last November have produced Republican majorities in both the House and the Senate. We've been hearing a lot about how big these majorities are, especially in the House, which hasn't seen this many Republicans since the presidency of Harry Truman. And joining us to talk about this seismic shift on Capitol Hill is NPR's senior editor and correspondent, Ron Elving. Ron, we keep hearing about the big new majority in the House. Remind us why this year is so remarkable.
RON ELVING, BYLINE: It's a big class. Two-hundred-and-forty-six Republicans are expected to take the oath tomorrow. And that is the most since the Congress elected in 1946. The last time the Republicans had a larger majority sworn-in was in 1929, when they had about 62 percent of the seats.
SIEGEL: So how much difference do a dozen seats make?
ELVING: It gives the speaker more breathing room. The speaker is likely to worry a little less about being hamstrung by, say, a handful of its dissidents. It lets the leadership think big about legislation and really, the biggest majorities in history have tended to make laws that really changed the country. The big Democratic majorities in Lyndon Johnson's era 50 years ago passed the Voting Rights Act and Medicare and the Great Society programs. The big Democratic majority six years ago passed Obamacare.
SIEGEL: Franklin Delano Roosevelt in the 1930s had even bigger majorities on the hill.
ELVING: Yes, more than 330 seats and 77 percent of the House, at his peak. And that majority passed the Wagner Act just 80 years ago this year, giving labor unions economic and political clout. And then when the Republicans came back after World War II and won that big majority I mentioned in 1946, they curtailed the Wagner Act with the Taft-Hartley Act and made it stick over Harry Truman's veto.
SIEGEL: Now, it's not just that there are more Republicans in the House and they have a bigger majority, but the huge change is also that the Senate is now in Republican hands, too - more significant?
ELVING: In a way. It is the first time in the Obama presidency that the Republicans have had both chambers under their control. And they have a few votes to spare in the Senate, having risen all the way to 54 seats there.
SIEGEL: But that doesn't give the GOP the 60 votes that they would need to close off filibusters and really run the show, under the rules of the Senate.
ELVING: That's right, and they're going to have trouble finding six crossover votes in this environment. You know, they beat some of their best prospective crossovers, in the sense of Democrats who might have voted with them on some of these issues. And they would need more than a dozen crossovers if they're going to override a presidential veto. That takes a two-thirds majority. And we may see vetoes and attempts at overrides very soon on issues such as the Keystone pipeline.
SIEGEL: And in the House, are the Republicans secure now for the time being, with such a big majority?
ELVING: It would seem so. We should mention that the last two times Republicans had this many seats in the House, they had disastrous elections at the very next cycle and lost control. But that's far less likely now. The regional base of the Republican Party has shifted. The last time they had this many seats, they had very few in the South. Now that's the bedrock of their majority. And in the rest of the country, Republican seats are largely locked in by the district maps that will be in effect until after 2020.
SIEGEL: OK. Thank you, Ron.
ELVING: Thank you, Robert.
SIEGEL: That's NPR editor and correspondent Ron Elving.