Maybe it is something in the water. Republican districts along the banks of the Ohio River are in danger. In Indiana and Kentucky in particular, there are very conservative districts that threaten to boot out their Republican incumbents.

A boat ride down the Ohio River would pass by the Indiana districts of John Hostettler and Mike Sodrel and the Kentucky district of Geoff Davis, three of the most vulnerable incumbents in the nation. If we take geographic license and add to these three the northern Indiana district of Chris Chocola, you find four conservative districts where moderate Democrats might replace conservative Republicans.

These four districts are atypical. If you look at a list of the twenty-five most vulnerable House Republicans, it is hard to find more than a handful who represent districts where Bush beat Kerry by more than 10 points: Tom DeLay’s open seat is in danger for quirky ballot issues, Charles Taylor is running against former football star Heath Shuler, Don Sherwood has been hobbled by illness and personal problems and freshman Thelma Drake faces a strong opponent and outside group spending.

Aside from these outliers, there are 15–20 endangered Republicans who are in Democratic- or barely Republican-leaning districts. Those moderate Republicans who lose will be replaced by liberal Democrats, and the trend toward polarization of the political parties in the House will deepen.

The four Indiana and Kentucky districts, however, are not swing districts represented by moderates.

Using the rankings of political scientists Howard Poole and Keith Rosenthal (voteview.com), Chocola, Davis, Hostettler and Sodrel are among the most conservative 30 percent of the House. Chocola was ranked as the 23rd most conservative member out of 435. And President Bush dominated the districts, winning Chocola’s by 13 points, Sodrel’s by 19, Hostettler’s by 24 and Davis’s by a whopping 27. Statewide, Bush won Indiana and Kentucky by about 20 points. So why are they in trouble?

First, the political climate. In addition to the national Democratic trend, almost every governor in the midwest, Republican or Democrat, is unpopular. Mitch Daniels in Indiana has a job approval rating in the high thirties. He has been bogged down on issues of taxes and even proposed changes to daylight savings time.

Ernie Fletcher is an even greater drag on Republicans in Kentucky. With Bob Taft in neighboring Ohio and Frank Murkowski in  Alaska (who has lost in the primary), Fletcher is part of an exclusive club of governors with approval ratings lower than 25 percent. This is a feat that is hard to achieve in politics. Fletcher has been dogged by charges of patronage abuse and was indicted on several misdemeanor counts. Recently, the charges were dropped, with Fletcher admitting wrongdoing.

In addition to the poor political climate, Democrats have fielded a very strong group of conservative Democrats. Baron Hill and Ken Lucas lost to Sodrel and Davis in 2004. In the 108th, Hill’s voting record was among the most 25 percent conservative for Democrats. Lucas was the fourth most conservative Democrat in the House. Hostettler faces elected sheriff Brad Ellsworth. Chocola faces a popular businessman Joe Donnelly. All are running significantly to the right of the national Democratic Party.

Finally, throw in weakness and inexperience. Sodrel and Davis are freshman, Chocola a sophomore, and while Hostettler has served six terms, he has a history of not raising enough money and winning races by a smaller-than-expected margin.

On election night, the polls will close first in Kentucky and Indiana (at 6:00 EST). Don’t be surprised to see several conservative Democrats taking a celebratory dip in the Ohio River.

Fortier is a research fellow at the American Enterprise Institute.