In an election season when control of Congress may hinge on any one of a handful of close senatorial races, the environment could play a decisive role in determining the political makeup of the government for the next two years. A GOP-controlled Senate, if Republicans gain seats, would no doubt be more receptive to Bush administration proposals that have in some cases met with criticism from environmental groups, scientists and public health professionals.

In the last two years, Senate Democrats, with the help of moderate Republicans, have thwarted Republican-led efforts to drill for oil in National Monuments (votes) and in the Arctic National Wildlife Refuge (votes). This summer, when the Bush administration and congressional Republicans proposed a controversial forestry policy that experts say would result in increased wildfire danger and heavier logging on public lands, Democrats hit the brakes. On the other hand, many Democrats joined with Republicans this summer to defeat significant gas mileage improvements for automobiles (votes), disappointing environmentalists and energy efficiency advocates.

Looking ahead, the stakes couldn't be higher. Federal transportation funding, which affects transit and anti-sprawl efforts, and toxic cleanups under Superfund are just two of the high-profile issues legislators will take up in 2003. Negotiations toward a national energy bill and judicial confirmations may also be affected by election outcomes.

Below is some basic information on key Senate races. Polling numbers are from Zogby, unless noted. Most polling data is from Oct. 10-15, as reported in the New York Post. Also provided are ratings from League of Conservation Voters (LCV). Separate pages contain information on ballot measures and web links.

South Dakota - Tim Johnson (D) vs. John Thune (R)

• Thune earned a zero percent LCV rating in 2001 as South Dakota's lone Representative in the House.
  
• Johnson earned a 61 percent LCV rating in 2001 in the Senate.
  
• Thune led 45-43 in recent polling.
  

• Wellstone earned a 100 percent LCV rating in 2001 in the Senate.
  
• Wellstone led 46-37 in recent polling.
  

• Carnahan earned a 63 percent LCV rating in 2001 in the Senate.
  
• Talent led 47-41 in recent polling.