Congressman Ron Paul may be a long shot to win the Republican presidential nomination, but he runs competitively with President Obama right now.

The latest Rasmussen Reports national telephone survey of Likely Voters shows Paul picking up 37% of the vote, while the president earns 41%. The Texas congressman joins Mitt Romney, Michelle Bachmann, and Rick Perry as candidates within hailing distance of the president at this time.

Rudy Giuliani is another potential candidate who is considered a long shot for the nomination but is competitive with the president. The former mayor of New York City trails Obama by five, 44% to 39%.

But the real story in the numbers is that the president continues to earn between 41% and 49% of the vote no matter which Republican is mentioned as a potential opponent. This suggests that the race remains a referendum on the incumbent more than anything else.

Two Republicans can’t even get to 30% against the president. Businessman Herman Cain and former Utah Governor Jon Huntsman, who served as Obama's ambassador to China, each earn 28% support. New Jersey Governor Chris Christie and former Alaska Governor Sarah Palin, considered unlikely to run by most observers, trail the president by seven and nine points respectively. Former Pennsylvania Senator Rick Santorum trails by 14.