Following up on yesterday's article, "Long-term trends show Democratic Party moving to the left" (which aimed to provide context to the left vs. center fight over the Democratic Party the Huffington Post wrote about yesterday), here is some more detail on the long-term ideological trends of the Democratic and Republican parties in the U.S. Senate. They largely confirm conventional wisdom, but not entirely. Among the findings:
All of the information below is based on DW-Nominate scores, which are the only available long-term ideological voting scorecard for Congress. DW-Nominate is based on roll call votes, and uses a negative 1.000 to positive 1.000 scale. The lower the number, the more left-wing a party or Senator is considered to be on economic issues.
- Within the Senate, Democrats are moving to the left, Republicans are moving to the right, and he two parties are now further apart from each other than ever.
- Since the 1960's, the left-ward trend for Democrats outside the south has slowed. It even briefly reversed itself in the 1970's and 1980's. Still, Senate Democrats today, both inside and outside the south, are more left-wing than ever.
- As a collective decade, the 1960's were the most fertile time ever for progressive legislation. For a single administration, the best opportunity was actually the Carter years. When they had 60 votes in 2009, Democrats had a roughly similar legislative opportunity to the 1977-1980 period. In 2010, the opportunity is more akin to the 1961-1968 period. Were it not for the filibuster, this would be the most left-wing federal government of all time (but hey, Democrats could get rid of the filibuster anytime via the nuclear option, they just choose not to do so).
1. Democrats are moving left, Republicans are moving right, and polarization is increasing
Conventional wisdom is that the two major parties are moving away from each other. Democrats are moving left, and Republicans are moving right, as the parties shift into primarily ideological coalitions. This appears to be exactly correct:
Senate DW-Nominate mean, by party, by decade
Democrats had a sharp move to the left during the 1940's to 1960's period, and then again in the 1990's and 2000's. Republicans started further out on the right than Democrats began on the left, and began a hard right turn in the 1980's.
2. Left-wing turn for Democrats not just because southern Democrats left the party
Like many others, I had assumed that the Democratic shift to the left was largely just conservative southern Democrats moving out of the party. However, a look at DW-Nominate scores only for Democratic Senators not from the 11 states that once formed the Confederacy shows that some of the movement was caused by that phenomenon, but not all of it (number of Senators in parenthesis):
Democratic non-Southern Senators, mean DW-nominate score by decade, 1930-2010
1930's: -0.093 (220)
1940's: -0.160 (175)
1950's: -0.291 (157)
1960's: -0.370 (224)
1970's: -0.357 (218)
1980's: -0.338 (185)
1990's: -0.384 (201)
2000's: -0.418 (223)
Outside of the south, there was rapid left-wing movement among Democratic Senators from the 1930's to the 1960's. That was followed by a period with some rightward backsliding, which was itself followed by a new period of left-wing movement. By 1993-1994, the Democratic Senate caucus outside of the south was once again as left-wing as it was in the 1960's. By the most recent decade, it had surpassed the 1960's:
Democratic non-Southern Senators, mean DW-nominate score by Congress, 1989-2010
101st: -0.352 (41)
102nd: -0.364 (43)
103rd: -0.374 (44)
104th: -0.382 (39)
105th: -0.398 (38)
106th: -0.406 (37)
107th: -0.408 (42)
108th: -0.410 (40)
109th: -0.415 (42)
110th: -0.420 (46)
111th: -0.435 (53)
It is also worth noting that the current decade has equaled the 1930's and 1960's for Democratic strength outside of the south.
3. The middle of the Senate
Means don't tell you much about the possibility of passing legislation. For that, medians are required. Here is a look at the DW-Nominate score for the 51st vote in the Senate from 1961 to 2010:
51st Senate vote, DW-Nominate, 1961-2010
Light blue signifies Democratic control of Senate and White House; purple signifies split control, bright red signifies Republican control
These numbers show pretty clearly that the 1960's were indeed the peak decade for the possibility of progressive legislation. With a Democrat in the White House, and the 51st vote consistently in the range of
0.1 to 0.2, there was fertile ground for the passage of Great Society legislation. It is only in 2009 that the opportunity surpassed that of the 1960's. Claire McCaskill is easily the most left-leaning 51st vote of all time.
However, as we all know, 51 votes don't seem to matter much these days. So, here is a look at the 60th vote in the Senate from 1961-2010:
60th Senate vote, DW-Nominate, 1961-2010
(Before 1975, cloture required 67 votes, not 60 votes. The pre-1975 period still looks at the 60-vote threshold for comparison purposes.
With a 60-vote threshold, the current government is not an improvement on past Democratic trifectas. The 1977-1980 period was comparable to 2009, and the 1963-1968 period is comparable to the post-Massachusetts special election setup. Having Ben Nelson as the deciding vote is much worse than having Claire McCaskill as the deciding vote.
The bottom line of all this is that even though the Democratic Party has moved to the left, overall the federal government has not, even under a Democratic trifecta. The main reason for this is that any Democratic movement to the left since the 1960's has been cancelled out by Republican moves to the right. As such, if we want a more progressive government, it will require not just more and better Democrats, but also better Republicans. Given the control the conservative movement has over the Republican Party these days, that is an extremely tall task. However, the continuing decline of moderate Republicans has, to date, made it impossible to elect a Senate further to the left of what this country experienced even 45 years ago.