Using a detailed quantitative model, an Indiana State University political scientist is forecasting that the Republicans will have a much greater influence on Congressional and legislative redistricting during the 2010 Census cycle than in any of the previous four cycles.

The study -- published in The Forum: A Journal of Applied Research in Contemporary Politics by professor Carl Klarner -- looks at the likelihood of which party will control the nation's governorships and state legislatures after the 2010 election. It then applies these probabilities to redistricting -- the process of drawing new district lines to account for population shifts in the decennial Census. Klarner's study takes into account the varied redistricting process in specific states, including states that have processes not subject to party influence.

Klarner concluded that the GOP will have untrammeled redistricting authority over 125 U.S. House seats, compared to just 62 for the Democrats. Meanwhile, 43 seats will be determined by nonpartisan or bipartisan commissions, or are in states with just one U.S. House seat.

The remaining 205 U.S. House districts would be drawn under conditions of divided government.

Looking at the four previous rounds of Congressional redistricting, Klarner found that such a Republican tilt is unprecedented.

Right after the 2000 Census was completed, the Democrats held redistricting control of 143 seats, compared to 68 seats for the GOP. And the Democratic edge was even larger following the 1970 Census (126 to 39), the 1980 Census (171 to 54) and the 1990 Census (124 to 5).

Klarner did not quantify the likely impact on state legislative redistricting, but since there is broad procedural overlap between the redrawing of state and federal lines, a stronger-than-usual GOP lean is expected for state legislative redistricting as well.

But Klarner also cautioned that the numbers show that a strong plurality of seats are likely to be decided by divided government, and a clear majority will be decided either by divided government or nonpartisan methods. The statistics also do not factor in the possibility of the courts taking over the process in certain states, which they have done often in the past.

Klarner's forecast was made using calculations that were current as of Sept. 18. His model predicts that Republicans will add a net of 15 legislative chambers and nine governorships.

That's broadly similar but not identical to what Governing is predicting. Governing's model -- which is based largely on reporting from state and national sources, rather than on quantitative estimates -- predicts a net GOP gain of eighteen chambers and seven governorships.

Klarner's model uses such national factors as presidential approval ratings, the change in per capita income, historical patterns of losses during midterm elections and the partisan trends in voters' generic ballot preferences. It also uses a range of state-based factors, including incumbency and the availability of a straight-ticket voting option.

Klarner's model predicted a partisan switch in the state senates of Alabama, Alaska, New York, North Carolina and Wisconsin, as well as the state houses of Alabama, Indiana, Iowa, Kentucky, Montana, New Hampshire, North Carolina, Ohio, Pennsylvania and Wisconsin. All are poised to move in the Republicans' direction.