Democratic margins and victories
In seizing majority control of the Senate in the 2006 midterm elections, the Democrats managed to do it the hard way. They knocked off six incumbent Republican senators. In addition, not only did each of the 15 Senate Democrats seeking re-election emerge victorious, but Democrats also retained two open seats (Minnesota and Maryland) and a seat held by a Democraticcaucusing independent (Vermont). Thus, Democrats swept all 18 Democratic-held seats. Altogether, Democratic candidates won 24 of the 33 Senate seats that were contested. Considering the six Republican incumbents defeated in Pennsylvania, Rhode Island, Virginia, Montana, Missouri and Ohio, the GOP lost 40 percent of the Republican-held seats contested in 2006.
It isn’t easy for one party to defeat at least six incumbent senators from the other party. In fact, in the 46 opportunities during the 23 biennial elections held from 1960 through 2004, it had happened only twice. Republicans defeated nine incumbent Democrats in 1980. In 1986, when Democrats recaptured six of the nine incumbent-held seats they had lost six years earlier, Democrats beat seven incumbent Republicans. Indeed, incumbents had become so entrenched in Congress in recent years that no party lost more than five incumbent members of the House (where all 435 seats are contested every two years) in any election after 1996 and before 2006. So, when Democrats defeated six Republican senators earlier this month, it was a very big deal.
How did it happen? In a nutshell, in all six states where Republican senators lost, the Democratic candidates performed better among self-identified moderate voters in the ideological category (liberals, moderates and conservatives). In five of the six states, Democrats received significant majorities from independent voters in the party-identification category (Democrats, Republicans and Independents). In the sixth state (Rhode Island), where Republican Sen. Lincoln Chafee outpolled his Democratic opponent (Sheldon Whitehouse) among independents (55-45), it did not matter because (a) Democrats outnumbered Republicans by more than two-toone and (b) Mr. Whitehouse won a majority (52-48) among the 56 percent of the voters who identified themselves as moderates.
Consider the breakdown among moderates and independents in the five other states. In Virginia, where Democratic candidate Jim Webb defeated Sen. George Allen 49.6 percent to 49.3 percent, Mr. Webb won 56 percent of the votes of independents, who made up one-quarter of the voters. Even though conservatives (35 percent of the Virginia electorate) outnumbered liberals (21 percent), Mr. Webb crushed Mr. Allen (60 percent to 40 percent) among the 44 percent of the electorate calling themselves moderates. In Ohio, Democratic senatorial candidate Sherrod Brown soundly beat (55.9-44.1) two-term moderate Sen. Mike DeWine (who won re-election in 2000 by 24 points) because Mr. Brown achieved 65-35 majorities among both moderates (48 percent of the Ohio electorate) and independents (23 percent).
In the tight race in Missouri, where Claire McCaskill beat Republican Sen. Jim Talent (49.5-47.4), she outpolled him 51-43 among independents (25 percent of voters) in state where Democrats (37 percent) essentially equaled Republicans (38 percent). Although self-identified conservatives (37 percent of Missouri voters, 83 percent of whom voted for Mr. Talent) considerably outnumbered liberals (21 percent of voters, 83 percent of whom supported Mrs. McCaskill), the Democratic candidate won because she outpolled the incumbent (62-35) among the 43 percent of Missouri voters who called themselves moderates. In Montana, which President Bush won by 25 points in 2000 and 21 points in 2004, Republican voters this year outnumbered Democrats (39-32) and conservatives exceeded liberals by a 34-19 margin. However, Democratic senatorial candidate Jon Tester still managed to beat three-term Montana GOP Sen. Conrad Burns because independents (29 percent of voters) and moderates (47 percent of voters) supported Mr. Tester over Sen. Burns by 59-35 and 59-38 margins, respectively. Pennsylvania’s Democratic candidate, Bob Casey Jr., beat two-term Republican incumbent Rick Santorum by more than 17 points in large part because 72 percent of independents and 65 percent of moderates voted for Mr. Casey.
Of course, the Republicans’ problems with independents and moderates were not confined to the six losing GOP senators. The national exit poll for House races revealed that Democratic candidates achieved a 22-point advantage (60-38) among the 47 percent of the electorate calling themselves moderates and an 18-point advantage among the 26 percent of voters who were independents. In making significant contributions to the overall 54-46 Democratic advantage in House races across the country, these blowout Democratic majorities among moderates and independents augmented the slight advantage Democrats (38 percent of voters) held over Republicans (36 percent) and overwhelmed the large advantage conservatives (32 percent of the electorate) held over liberals (20 percent).
The 2000 presidential election, when George W. Bush beat Al Gore by five electoral votes despite receiving a smaller share (47.87 percent versus 48.38 percent) of the popular vote, was arguably a closer election than the 1960 victory (49.72-49.55) by John Kennedy, who received 84 more electoral votes than Richard Nixon. As close as the 2000 presidential popular vote was (Mr. Gore received 537,000 more votes than Mr. Bush, although the ultimately deciding factor was Mr. Bush’s 537-vote margin in Florida), the popular vote for the Senate turned out to be much closer. In winning 18 of the 33 Senate races in 2000, Democrats outpolled Republicans by a mere 50,001 votes (36,971,061 to 36,921,060). The two-party percentage breakdown was 50.03 to 49.97, and when all the dust had settled, the Senate was deadlocked 50-50 after the 2000 elections.
How the early 2001 50-50 Senate, where Vice President Dick Cheney was available to cast tie-breaking votes, evolved into a 5149 Democratic majority after the 2006 elections offers some interesting arithmetical insights. In May 2001, Vermont Republican Jim Jeffords bolted the GOP; began caucusing with the Democrats; and thus flipped control of the Senate to Democrats (51-49). Including the special election in Missouri, Republicans won 22 of the 34 Senate seats contested in 2002 by receiving 21.6 million (52.05 percent) of the 41.4 million votes cast. The GOP regained a narrow 51-49 majority. In 2004, Democratic senatorial candidates received 42.5 million votes, 4.1 million more votes than Republican candidates received (38.4 million votes). But the GOP won 19 of the 34 Senate contests.
Thus, after the 2004 elections, Republicans enjoyed a 55-45 Senate majority — despite the fact that Republican candidates in these 100 contests had received fewer total votes than Democrats did. Indeed, liberals (particularly Hendrik Hertzberg of the New Yorker, as well as Brad DeLong and other left-wing bloggers) have justified the Democratic Party’s filibustering and other obstructionist tactics in the Senate in part because Democratic candidates in the previous three elections (2000, 2002 and 2004) had cumulatively received nearly 2.5 million more votes than Republican candidates (99.35 million versus 96.89 million).
Indicative of the monstrous size of the Democratic blowout in this year’s Senate elections is the fact that Democratic candidates outpolled their Republican opponents by nearly 7.5 million votes (32.974 million vs. 25.547 million). Among the two-party vote, Democrats achieved a staggering 12.7 percentage-point margin (56.35 percent to 43.65 percent). No wonder they won 24 of the 33 contests this year, which will give them a 51-49 majority in the 110th Congress beginning in January. Over the last three elections (2002, 2004 and 2006), Democratic senatorial candidates have received nearly 10 million more votes than Republican candidates (95.352 million versus 85.512 million). In forging their 51-49 Senate majority and compiling their 52.7 percent to 47.3 percent advantage in the voting booth, Democrats received 11.5 percent more votes than Republicans.