Saturday, October 30, 2010

A Note to Readers

On election night, I will be providing live updates of the results. I will update an election board, which will show the status of the most vulnerable House and Senate seats, along with a running probability of a Republican takeover in each chamber. Please visit my site so that you can all receive this information in realtime.

-Jacob

FINAL List of Vulnerable House Seats

In the final analysis of individual U.S. House seats, 89 Democrats and six Republicans are now listed as vulnerable. In the past week, Chellie Pingree (ME-1) was added to the list of vulnerable Democratic Representatives.

As the reader may notice, the Republicans are likely to retake control of the U.S. House of Representatives. The Democrats will probably win four or five Republican seats. However, the Republicans have at least a 90 percent probability of winning each of 41 Democratic seats. They have at least a 50 percent probability of winning each of the next 22 most vulnerable seats. They even have over a 10 percent probability of winning each of the 64th through 82nd most vulnerable seats. This analysis implies that the Republicans are expected gain approximately 41 + 1/2*41 = 62 seats and lose about four seats. Thus, the Republicans are poised to net about 58 seats, while they only need to gain 39 seats to take control of the House.

Correction: Note that WV-3 is not open.

Democrats by State (Open seats in bold)


Democrats by Vulnerability (Open seats in bold)


Republicans (Open seats in bold)

FINAL House Prediction: Republicans Gain 52

Based on polling data released over the last nine months, Republicans are expected to gain between 41 and 62 seats in the U.S. House of Representatives (with a 90 percent level of credibility). According to the model, the most likely outcome is about a 52 seat gain by Republicans, one more seat than the previous estimate. The Republicans seem to be poised to retake control of the U.S. House of Representatives with the largest electoral landslide since 1948. In fact, based on a Monte Carlo simulation, the Republicans have a 97 percent probability of retaking the House.

A statistical model that analyzes the results of 15 independent polling firms indicates that Republicans lead Democrats by a margin of 3.9 percent on the so-called generic ballot--a measure of national voter preference between the two major congressional caucuses. This figure is 0.6 percent greater than the mid-October estimate. The final estimate implies that, if the election were held today, Republicans would achieve approximately a 27 seat majority over the Democrats--a historically modest, but commanding advantage.

The charts below provide the change in voter preferences over time, along with the probability distribution of the number of seats gained by Republicans on election day. See my April 30, 2010 post for an explanation of my methodology.


Friday, October 29, 2010

FINAL Senate Prediction: Republicans Gain Seven

Safe Democratic, 8 Seats (15 percent+) :
CT (Dodd)
DE (Kaufman)
Inouye (HI)
Mikulski (MD)
Schumer (NY-A)
Gillibrand (NY-B)
Wyden (OR)
Leahy (VT)

Strong Democratic, 2 Seats (5.0 -15.0 percent):
Boxer (CA)
Murray (WA)

Weak Democratic, 2 Seats (0.0 - 5.0 percent):
IL (Burris)
WV (Byrd)

Weak Republican, 4 Seats (0.0 - 5.0 percent):
Bennet (CO)
NH (Gregg)
Reid (NV)
PA (Spector)

Strong Republican 5 Seats (5.0 - 15 percent):
Grassley (IA)
KY (Bunning)
OH (Voinovich)
MO (Bond)
Feingold (WI)

Safe Republican 16 Seats (15.0 percent+):
AK (Murkowski)
Shelby (AL)
McCain (AZ)
Lincoln (AR)
FL (LeMieux)
Crapo (ID)
IN (Bayh)
Isakson (GA)
KS (Brownback)
Vitter (LA)
ND (Dorgan)
Burr (NC)
Coburn (OK)
DeMint (SC)
Thune (SD)
UT (Bennett)

Saturday, October 23, 2010

Most Vulnerable House Seats: Situation Continues to Worsen for Democrats

In the latest analysis of individual House Seats, seven additional Democrats are now listed as vulnerable. The seven Democrats are House veterans Sanford Bishop Jr. (GA), Leonard Boswell (IA), Bruce Braley (IA), Bob Etheridge (NC), James Oberstar (MN), Nick Rahall (WV), and Ike Skelton (MO). Hence, 88 Democrats are listed as vulnerable, while only six Republicans are at risk of losing.

As the reader may notice, the Republicans are likely to retake control of the U.S. House of Representatives. The Democrats will probably win four or five Republican seats. However, the Republicans have at least a 90 percent probability of winning each of 37 Democratic seats. They have at least a 50 percent probability of winning each of the next 26 most vulnerable seats. They even have over a 10 percent probability of winning each of the 64th through 82nd most vulnerable seats. This analysis implies that the Republicans are expected gain approximately 37 + 1/2*44 = 59 seats and lose about four seats. Thus, the Republicans are poised to net about 55 seats, while they only need to gain 39 seats to take control of the House.

Democrats by State (Bold indicates open seat)


Democrats by Rank (Bold indicates open seat)


Republicans (Bold indicates open seat)

HOUSE UPDATE: Republicans Remain Poised to Win 50+ Seats

Based on polling data released over the last nine months, Republicans are expected to gain between 39 and 63 seats in the U.S. House of Representatives (with a 90 percent level of credibility). According to the model, the most likely outcome is about a 51 seat gain by Republicans, the same as the previous estimate. If the polling holds steady, Republicans seem to be poised to retake control of the U.S. House of Representatives with the largest electoral landslide since 1994. In fact, based on a Monte Carlo simulation, the Republicans have a 95 percent probability of retaking the House.

A statistical model that analyzes the results of 15 independent polling firms indicates that Republicans lead Democrats by a margin of 3.3 percent on the so-called generic ballot--a measure of national voter preference between the two major congressional caucuses. This figure is identical to the September estimate. The mid-October estimate implies that, if the election were held today, Republicans would achieve approximately a 25 seat majority over the Democrats--a modest, but decisive advantage.

Next week, I will publish a final estimate for the mid-term election. Per usual, the charts below provide the change in voter preferences over time, along with the probability distribution of the number of seats gained by Republicans on election day. See my April 30, 2010 post for an explanation of my methodology.

Friday, October 15, 2010

SENATE UPDATE: Republicans Predicted to Gain Six Seats

Safe Democratic, 7 Seats (15 percent+) :
CT (Dodd)
Inouye (HI)
Mikulski (MD)
Schumer (NY-A)
Gillibrand (NY-B)
Wyden (OR)
Leahy (VT)

Strong Democratic, 4 Seats (5.0 -15.0 percent):
Boxer (CA)
DE (Kaufman)
IL (Burris)
Murray (WA)

Weak Democratic, 2 Seats (0.0 - 5.0 percent):
Reid (NV)
WV (Byrd)

Weak Republican, 3 Seats (0.0 - 5.0 percent):
Bennet (CO)
NH (Gregg)
PA (Spector)

Strong Republican 4 Seats (5.0 - 15 percent):
Grassley (IA)
OH (Voinovich)
MO (Bond)
Feingold (WI)

Safe Republican 17 Seats (15.0 percent+):
AK (Murkowski)
Shelby (AL)
McCain (AZ)
Lincoln (AR)
FL (LeMieux)
Crapo (ID)
IN (Bayh)
Isakson (GA)
KS (Brownback)
KY (Bunning)
Vitter (LA)
ND (Dorgan)
Burr (NC)
Coburn (OK)
DeMint (SC)
Thune (SD)
UT (Bennett)

Wednesday, October 13, 2010

Most Vulnerable House Seats, Part IV

In the tables below, I assign probabilities to Republican gains in the 81 most vulnerable Democratic seats. I also list probabilities to Democratic gains in the six most vulnerable Republican seats.

As the reader may notice, the Republicans are likely to retake control of the U.S. House of Representatives. The Democrats will probably win four or five Republican seats. However, the Republicans have at least a 90 percent probability of winning each of 33 Democratic seats. They have at least a 50 percent probability of winning each of the next 23 most vulnerable seats. They even have over a 10 percent probability of winning each of the 57th through 75th most vulnerable seats. This analysis implies that the Republicans are expected gain approximately 33 + 1/2*42 = 54 seats and lose about four seats. Thus, the Republicans are poised to net about 50 seats, while they only need to gain 39 seats to take control of the House.

Democrats by State (Bold indicates open seat)


Democrats by Rank (Bold indicates open seat)


Republicans (Bold indicates open seat)

Sunday, October 10, 2010

Most Vulnerable House Seats, Part III

In the tables below, I assign probabilities to Republican gains in the 81 most vulnerable Democratic seats. I also list probabilities to Democratic gains in the six most vulnerable Republican seats.

As the reader may notice, the Republicans are likely to retake control of the U.S. House of Representatives. The Democrats will probably win four or five Republican seats. However, the Republicans have at least a 90 percent probability of winning each of 30 Democratic seats. They have at least a 50 percent probability of winning each of the next 26 most vulnerable seats. They even have over a 10 percent probability of winning each of the 57th through 75th most vulnerable seats. This analysis implies that the Republicans are expected gain approximately 30 + 1/2*45 = 52 seats and lose about five seats. Thus, the Republicans are poised to net about 47 seats, while they only need to gain 39 seats to take control of the House.


Democrats by State (Bold indicates open seat)



Democrats by Rank (Bold indicates open seat)



Republicans (Bold indicates open seat)

Saturday, October 2, 2010

HOUSE UPDATE: Bottom Falls Out of Democratic Party

Based on polling data released over the last nine months, Republicans are expected to gain between 39 and 62 seats in the U.S. House of Representatives (with a 90 percent level of credibility). According to the model, the most likely outcome is about a 51 seat gain by Republicans, up from the previous estimate of 48 seats. If the polling holds steady, Republicans seem to be poised to retake control of the U.S. House of Representatives with the largest electoral landslide since 1994. In fact, based on a Monte Carlo simulation, the Republicans have a 95 percent probability of retaking the House.

A statistical model that analyzes the results of 15 independent polling firms indicates that Republicans lead Democrats by a margin of 3.3 percent on the so-called generic ballot--a measure of national voter preference between the two major congressional caucuses. This figure is substantially greater than the August estimate of 2.0 percent. The September estimate implies that, if the election were held today, Republicans would achieve approximately a 25 seat majority over the Democrats--a modest, but decisive advantage.

Over the next two months, I will update this model and estimate Republican electoral gains. The charts below will provide the change in voter preferences over time, along with the probability distribution of the number of seats gained by Republicans on election day. See my April 30, 2010 post for an explanation of my methodology.