Coburn takes substantial lead in U.S. Senate race.

OKLAHOMA CITY - With less than 4 days until the election, the numbers for Oklahoma's open U.S. Senate seat are moving. Tom Coburn (R) has taken a significant lead over Brad Carson (D) for the first time since the primary.

SoonerPoll.com, a public opinion research firm in Oklahoma City, conducted the telephone poll of 498 statewide likely voters Wednesday and Thursday for Fox25 in Oklahoma City and KSWO in Lawton showing Coburn with 44.4%, Carson with 35.1%, Independent Sheila Bilyeu with 4.2%, and 16.3% still undecided. The margin of error was 4.4%.

In cross-party voting, Coburn has the advantage. A full 25% of Democrats report they will vote for Coburn, compared to Carson's 11.6% of Republican supporters. Carson is getting support of only half his own party, but 58.3% of Independents.

The most significant change was in the two major metropolitan areas. Coburn gained over 10% in each of Oklahoma's two largest media markets - Oklahoma City and Tulsa, while Carson lost 10% in Tulsa and 8% in Oklahoma City.

The number of undecided voters declined again this week, as both candidates pledged to stop negative campaigning.

A former Carson contributor, who was also the attorney for Dr. Coburn over the sterilization case, remained a centerpiece of Coburn's advertising this week. The ads focus on his personal knowledge of the case and how Carson declined to pull his Medicaid fraud ads even after knowing the charges were baseless.

Carson, however, began running ads announcing his decision to pull all negative ads paid for by his campaign, and to publicly encourage any and all outside groups to stop running negative campaign ads as well.