The Chairmen

Among Minnesota's Democratic congressional delegation there are two in top leadership positions; Jim Oberstar is Chairman of the House Transportation and Infrastructure Committee and Colin Peterson is Chairman of the House Agriculture Committee. Both have represented the state for a long time; Oberstar for over 25 years, Peterson for close to 20, and both represent large, mostly rural districts. But as we saw with their respective SILVER scores, they are quite different in how they vote, at least in the 111^th congress. While Colin Peterson had a slightly liberal for his district score of -.06, Jim Oberstar had a superstar level -.55. Let's take a look at their DW-Nominate scores over the entire course of their time in office to see if that changes our perception any.

What you see is that over the years Oberstar has become marginally more conservative while Peterson has made moves in the liberal direction. This becomes even more evident when you look at their current scores for the 111^th congress versus their mean and first year scores.

	111	mean	1st	+/- mean	+/- 1st	stddv
PETERSON	-0.175	-0.139	-0.103	-0.036	-0.072	0.0242
OBERSTAR	-0.539	-0.544	-0.550	0.005	0.011	0.0033

As we saw earlier, in the 111^th congress Peterson is voting more liberally then he has in the past and Oberstar is voting slightly more conservatively. What you can also see by looking at the standard deviation of their scores, as well as the +/- versus the mean and first year, is that Peterson's voting patterns have shifted more substantially over the years then Oberstar's, who has essentially the same score now as when he started.

What does this mean? Well, Jim Oberstar has been voting the same way for 25 years and Colin Peterson has ever so slightly become more liberal than when he first joined the congress. If we assume the PVI of the 7^th CD is the same now as it was in 1991 (a dubious assumption) then Peterson would've had a SILVER score of .08 in his first congress, compared to the -.06 he has so far this congress, a -.14 swing in the liberal direction. It's probably not incidental that his vote share has also risen steadily over the years to 72% in 2008. While Colin Peterson is no liberal, he is liberal for his district and getting more liberal every year.

Minnesota’s Congressional Delegation

In an effort to get a better understanding of the voting tendencies of our congressional delegation I compiled the DW-Nominate scores for all of Minnesota's politicians from the 111^th congress. DW-Nominate is a scoring system for politicians, running from around -1 to 1, with -1 being very liberal and 1 being very conservative. There's a few ways to look at these numbers; first we'll just look at the raw DW-Nominate scores.

Representative	DW-N Score
ELLISON	-0.58
OBERSTAR	-0.54
MCCOLLUM	-0.44
Average Dem	-0.35
WALZ	-0.28
PETERSON	-0.18
PAULSEN	0.54
Average GOP	0.63
KLINE	0.69
BACHMANN	0.71

This is probably not too shocking of a chart, for the most part reflecting the conventional wisdom about the liberal/conservative spread of our state's delegation, except for maybe Jim Oberstar who ranks as more liberal then I would have suspected. Now let's adjust those scores to the party average, so for instance, the Democrats average DW-Nominate score was -.35, so Keith Ellison would then score a -.23 and Colin Peterson would score a .17, meaning Ellison is more liberal than the average Democrat and Peterson is more conservative.

Representative	DW vs average
ELLISON	-0.23
OBERSTAR	-0.19
MCCOLLUM	-0.09
WALZ	0.07
PETERSON	0.17
PAULSEN	-0.09
KLINE	0.05
BACHMANN	0.08

Again, nothing to ground breaking; Paulson is more liberal than the average GOPer, Walz and Peterson are more conservative than the average Democrat. The next thing I want to do is take a look at the PVI, partisan voting index, for the districts. PVI measures how Republican or Democratic a district is by averaging the districts results of the past two presidential elections and comparing them to the overall results. The difference between the two numbers is the districts PVI score, which for the purposes of this exercise we'll format the same way as the DW nominate scores, positive for GOP leaning districts, negative for Democratic leaning districts.

Representative	PVI	PVI vs Average
ELLISON	-23	-14
OBERSTAR	-3	6
MCCOLLUM	-13	-4
WALZ	1	10
PETERSON	5	14
Average Dem	-9
PAULSEN	0	-11
KLINE	4	-7
BACHMANN	7	-4
Average GOP	11

Tim Walz and Eric Paulson reside in the two swing districts in the state, according to PVI, with Oberstar's 8^th and Kline's 2^nd on the verge of being swingy. Obviously Colin Peterson's 7^th is in a bit of a special category, being solidly Republican yet sending Peterson back to congress year after year.

Now we can take these two measures and combine them into one number that will tell us how partisan a member is for their district on a rough -1 to 1 scale. We'll call this number the Selectively Integrated Legislator Variance Evaluation Resource, or SILVER for short.

Representative	SILVER
ELLISON	-0.03
OBERSTAR	-0.55
MCCOLLUM	-0.04
WALZ	-0.15
PETERSON	-0.06
PAULSEN	0.14
KLINE	0.31
BACHMANN	0.26

What stands out to me on this chart is when put into the context of their districts Oberstar is quite a bit more liberal than his colleagues; in fact he's 7^th among all Democrats in SILVER. My representative, Keith Ellison, whom the conventional wisdom has as an uber-liberal, is right around average. I also think this is vindication of a sort for Colin Peterson who has taken a lot of flak for some of his recent votes but is, by this measure, more liberal then Keith Ellison or Betty McCollum.