Let me start by saying this was a gauntlet. I started by collecting election data for the Presidential Election of 2004 and the Senate Elections of 2004 and 2006. I then parsed the results and created a massive table while incorporating our projections into a 2008 metaset. From here I just did the simple division necessary to compute the Coattail Coefficient.

The table below illustrates the outcome of our study. The "XXX Pres Coefficient" column represents the calculation previously prescribed in our previous article on coattails; if the result of the simple division is greater than 1, the Senate candidate is over performing relative to that party's Presidential nominee. A number below 1 implies the opposite. For Senate races that occurred in 2006 I used the 2004 Presidential result from that state as the comparator. The 2008 data is drawn from our projections, and the 2004 data is provided by the Federal Election Committee.

The furthest column to the right, Winner's Coattail, corresponds to the Coattail Coefficient of the party that won the given Senate Election. The "<" and ">" illustrate whether the eventual winner of the given Senate seat had a larger coefficient than the competition. The "<" is used when the victor did in fact have a larger coefficient, while the ">" implies the opposite. I have bolded all races in which the actual or projected margin ranged between zero and six percent. I encourage you to take a detailed look at the table below, but when you're done don't forget to continue reading.

State           Year    Dem Pres     Rep Pres     Winner's
                       Coefficient  Coefficient   Coattail
Nebraska        2006       1.95        0.55      < 1.95 (D)
North Dakota    2004       1.92        0.50      < 1.92 (D)
Maine           2006       0.38        1.66      < 1.66 (R)
North Carolina  2006       1.58        0.53      < 1.58 (D)
Indiana         2004       1.57        0.62      < 1.57 (D)
Rhode Island    2008       1.55        0.80      < 1.55 (D)
Maine           2008       0.77        1.53      < 1.53 (R)
West Virginia   2008       1.51        0.65      < 1.51 (D)
Arkansas        2008       1.49        0.93      < 1.49 (D)
West Virginia   2006       1.49        0.60      < 1.49 (D)
South Dakota    2008       1.49        0.72      < 1.49 (D)
Indiana         2006       0.00        1.46      < 1.46 (R)
Idaho           2004       0.00        1.45      < 1.45 (R)
New Mexico      2006       1.44        0.59      < 1.44 (D)
Montana         2006       1.41        0.74      < 1.41 (D)
Iowa            2004       0.57        1.41      < 1.41 (R)
Arizona         2004       0.46        1.40      < 1.40 (R)
Hawaii          2004       1.40        0.46      < 1.40 (D)
Wisconsin       2006       1.35        0.60      < 1.35 (D)
New Hampshire   2004       0.67        1.35      < 1.35 (R)
Mississippi-A   2008       0.92        1.29      < 1.29 (R)
Louisiana       2008       1.28        0.77      < 1.28 (D)
West Virginia   2004       1.28        0.79      < 1.28 (D)
Florida         2006       1.28        0.73      < 1.28 (D)
Illinois        2004       1.28        0.61      < 1.28 (D)
Nevada          2004       1.28        0.70      < 1.28 (D)
Montana         2006       1.27        0.82      < 1.27 (D)
Wyoming-A       2008       0.75        1.27      < 1.27 (R)
Delaware        2006       1.26        0.60      < 1.26 (D)
Ohio            2004       0.74        1.26      < 1.26 (R)
Arkansas        2004       1.25        0.81      < 1.25 (D)
Oregon          2004       1.23        0.67      < 1.23 (D)
Connecticut     2004       1.22        0.73      < 1.22 (D)
Wyoming-B       2008       0.82        1.22      < 1.22 (R)
Virginia        2004       1.21        0.80      < 1.21 (D)
Vermont         2004       1.20        0.63      < 1.20 (D)
Virginia        2008       1.19        0.72      < 1.19 (D)
Maryland        2004       1.16        0.79      < 1.16 (D)
Ohio            2006       1.15        0.86      < 1.15 (D)
Pennsylvania    2006       1.15        0.85      < 1.15 (D)
Vermont         2006       1.15        0.83      < 1.15 (D)
Tennessee       2008       0.84        1.14      < 1.14 (R)
Delaware        2008       1.14        0.74      < 1.14 (D)
Minnesota       2006       1.14        0.80      < 1.14 (D)
Hawaii          2006       1.14        0.81      < 1.14 (D)
Alabama         2008       0.90        1.12      < 1.12 (R)
New York        2004       1.12        0.60      < 1.12 (D)
Massachusetts   2006       1.12        0.83      < 1.12 (D)
New Mexico      2008       1.12        0.86      < 1.12 (D)
Kansas          2004       0.75        1.12      < 1.12 (R)
Alaska          2008       1.11        0.86      < 1.11 (D)
Michigan        2006       1.11        0.86      < 1.11 (D)
Iowa            2006       1.11        0.92      < 1.11 (D)
Kansas          2008       0.83        1.10      < 1.10 (R)
Nevada          2006       0.86        1.10      < 1.10 (R)
California      2006       1.09        0.79      < 1.09 (D)
Colorado        2004       1.09        0.90      < 1.09 (D)
Virginia        2006       1.09        0.92      < 1.09 (D)
Pennsylvania    2004       0.82        1.09      < 1.09 (R)
Alabama         2004       0.88        1.08      < 1.08 (R)
Washington      2006       1.08        0.87      < 1.08 (D)
Michigan        2008       1.08        0.84      < 1.08 (D)
Missouri        2006       1.08        0.89      < 1.08 (D)
Mississippi-B   2006       0.88        1.07      < 1.07 (R)
California      2004       1.06        0.85      < 1.06 (D)
New Hampshire   2006       1.06        0.91      < 1.06 (D)
Missouri        2004       0.93        1.05      < 1.05 (R)
South Carolina  2008       0.98        1.04      < 1.04 (R)
New York        2006       1.03        0.67      < 1.03 (D)
Wyoming-A       2006       1.03        1.02      > 1.02 (R)
Massachusetts   2008       1.01        0.58      < 1.01 (D)
Texas           2006       0.94        1.01      < 1.01 (R)
Georgia         2004       0.96        1.00      < 1.00 (R)
New Hampshire   2008       1.00        0.85      < 1.00 (D)
Illinois        2008       0.99        0.98      < 0.99 (D)
Colorado        2008       0.99        0.87      < 0.99 (D)
Mississippi-B   2008       0.97        0.99      < 0.99 (R)
Texas           2008       0.96        0.98      < 0.98 (R)
Minnesota       2008       0.72        0.98      < 0.98 (R)
Arizona         2006       0.98        0.97      > 0.97 (R)
Maryland        2006       0.97        1.03      > 0.97 (D)
Nebraska        2008       0.96        0.97      < 0.97 (R)
Florida         2004       1.03        0.95      > 0.95 (R)
Kentucky        2008       1.06        0.93      > 0.93 (R)
South Carolina  2004       1.08        0.93      > 0.93 (R)
North Carolina  2004       1.08        0.92      > 0.92 (R)
Georgia         2008       0.99        0.92      > 0.92 (R)
Rhode Island    2006       0.90        1.20      > 0.90 (D)
Louisiana       2004       1.12        0.90      > 0.90 (R)
North Carolina  2008       0.90        0.88      < 0.90 (D)
Tennessee       2006       1.13        0.89      > 0.89 (R)
Utah            2006       1.20        0.87      > 0.87 (R)
New Jersey      2008       0.86        1.02      > 0.86 (D)
Kentucky        2004       1.24        0.85      > 0.85 (R)
Oregon          2008       0.84        1.08      > 0.84 (D)
Oklahoma        2008       1.17        0.84      > 0.84 (R)
Idaho           2008       1.20        0.83      > 0.83 (R)
Oklahoma        2004       1.20        0.80      > 0.80 (R)
Alaska          2004       1.28        0.80      > 0.80 (R) 
Connecticut     2006     0.73/0.93     0.22    < 0.73/0.93 (D)

What does this massive compilation of data mean? The result is surprisingly straightforward and allows for a nice generalization. Focusing our attention towards the bottom of the table reveals that the winner, in a competitive race, rarely garnered a coefficient greater than 1. This result appears to be counterintuitive but just wait, it gets stranger; notice the large quantity of ">" signs towards the bottom of the table. Under this interpretation the candidate who can win more votes from the opposite party is the likely victory; its actually better to abandon your own party and run across the aisle. Using this result, a succinct postulate can be formed: if candidate A has a coefficient less than 1 and their opponent, candidate B, has a coefficient greater than 1, candidate A has the historic advantage.

Using the above postulate, what can then be said about the 2008 Senate races?

We'll start from the bottom and work our way up through the bolded races happening this year. Our first stop is Oregon. Oregon seems to be safely in Democratic hands, Smith (R) has a coefficient greater than 1 at 1.08, while his challenger Markley (D), is repping a 0.84. Merkley has also opened up a healthy four to five point lead in recent polling.

Moving on up; North Carolina is our next stop. Hagan (D) is currently leading our projection, but the coefficients in this race favor the incumbent Dole (R).

Georgia's like North Carolina, but the opposite. Martin (D) is trailing in the polls, but he's got the better coefficients.

Kentucky exemplifies our rule and seems to be safely in McConnell's (R) court.

Minnesota features a competitive three way race so I'm not exactly sure how our generalization applies, but here it goes. Franken's (D) coefficient is significantly below 1, in fact its the lowest coefficient in the field, but Coleman (R) is still maintaining a slight lead; in large part due to a very suspect St. Cloud State poll that showed 21% of the Minnesota electorate as undecided. Barkley could still make a run too, its impossible to tell.

Our little conclusion may give hope yet to Musgrove (D), the Democratic challenger in Mississippi-B. Musgrove's coefficient is below both 1 and his competitors coefficient, but recent polling has shown Wicker (R) with a significantly large lead.

The last on the list is Alaska, but after today's news of the Stevens' conviction, Begich (D) seems destined to the Senate.

Using just the conclusion of this report as a predictor, the Democratic Party stands to pickup Oregon, Georgia, Minnesota, Mississippi-B and Alaska. By my count that would put the Democratic caucus at the magical 60 Senator, filibuster proof majority.