The most interesting race in 2010 is tilting in a Republican direction, with GOP contenders Rand Paul and Trey Grayson both outpolling the top Democratic prospects. The latest survey from Rasmussen shows Grayson leading Daniel Mongiardo 53 to 33 percent and topping Jack Conway 52 to 32 percent. Paul beats Mongiardo 52 to 37 percent and bests Conway 50 to 36 percent.

The report contains an interesting bit of analysis about the sources of Paul’s and Grayson’s support:

Grayson runs slightly stronger among Republicans against both Democrats. Voters not affiliated with either major party heavily favor the Republicans over their Democratic opponents but go a bit more strongly for Paul than for Grayson.

The question is which Republican will edge the other next month as the two continue to pound each other on TV and the Internet. Since Paul is the son of maverick Republican Ron Paul, his success or failure in the May 18 primary is viewed as an early test of the power the Tea Party movement will have on other upcoming Republican contests and at the polls in November.

Fourteen percent (14%) of voters in the state view Grayson very favorably, while eight percent (8%) have an unfavorable opinion of him.

For Paul, very favorables are 21% and very unfavorables 12%.

Kentucky has a closed Republican primary, which means the independents leaning toward Paul will not get to vote for him, though so far his polling within the primary electorate has shown a double-digit lead. It’s a real race.