Get ready for a Missouri classic.

In the tradition of barnburner political races in the Show Me State, a poll came out Thursday showing favorites in the U.S. Senate campaign as essentially even.

Southwest Missouri Congressman Roy Blunt, a Republican, polled at 45 percent support, while Democratic Secretary of State Robin Carnahan got 44 percent support.

The poll, conducted Wednesday by the nationwide firm Rasmussen Reports, has a margin of error of plus or minus 4.5 percent.

In May's poll, Mr. Blunt led Ms. Carnahan in support by 50 percent to 42 percent.

Wednesday's poll also showed that the 500 Missouri likely voters surveyed had strong feelings about the oil spill in the Gulf of Mexico, with 82 percent saying it will have either a devastating or major impact on the environment.

The Carnahan campaign has pointed out Mr. Blunt's history of contributions from oil companies and his membership on the House Energy and Commerce Committee. The Blunt campaign has referenced a report by factcheck.org that points to distortions and exaggerations contained in the Democrat's recent claims.

The candidates are looking to succeed Kit Bond, a Republican member of the Senate since 1987.

There are three Democrats, nine Republicans and five other candidates who will appear on the Aug. 3 primary ballot. The general election is Nov. 2.

For more about the poll, click here.