The 18 states allowing for recall are as follows: Alaska, Arizona, California, Colorado, Georgia, Idaho, Kansas, Louisiana, Michigan, Minnesota, Montana, Nevada, New Jersey, North Dakota, Oregon, Rhode Island, Washington and Wisconsin.
Read more: How to Recall a U.S. Senator | eHow.com http://www.ehow.com/how_2096900_recall-us-senator.html#ixzz15XlEyFUu
The United States Constitution, which actually contains the conditions and qualifications for holding a seat in the United States Senate, contains no provision for Congressional recall elections.
The United States Supreme Court held in U.S. Term Limits, Inc. v. Thornton, 514 U.S. 779 (1995), that "In light of the Framers' evident concern that States would try to undermine the National Government, they could not have intended States to have the power to set qualifications." The court also noted that the framers of the Constitution decided to "reject a proposal allowing for States to recall their own representatives, see 1 Farrand 20, 217..."