Election Day may not decide which party wins the Senate majority. Why?
1. Possible runoffs in Louisiana and Georgia. Alaska's tradition of delayed vote counts also could postpone the official results.
2. Republicans need to gain six seats to control the Senate. They could pick up five on Nov. 4, only to await a decisive Louisiana runoff Dec. 6. Even if they won that seat, a Jan. 6 runoff in Georgia possibly could return Republicans to the minority.
3. Many strategists expect a runoff in Louisiana. They say Democratic Sen. Mary Landrieu and top Republican challenger Bill Cassidy will struggle to exceed 50 percent on the crowded, all-parties ballot.
4. Congress' lame-duck session in November could prove unusually divisive and confusing if it's unclear which party will control the new Senate set to convene in January.
5. A potential Georgia runoff would take place three days after the new Congress is scheduled to open Jan. 3. Democrats hope for an upset win to replace retiring GOP Sen. Saxby Chambliss.