Political novice Rand Paul rode support from tea party activists to victory in Kentucky's Republican Senate primary Tuesday night, delivering a jolt to the GOP establishment and providing fresh evidence of widespread voter discontent in a turbulent midterm election season.

Paul had 59 percent of the vote — with returns counted from 29 percent of the precincts — to 37 percent for Secretary of State Trey Grayson, who had been recruited to run by the state's dominant Republican, U.S. Senate Minority Leader Mitch McConnell.

In a Democratic primary that commanded far less national attention, Attorney General Jack Conway led Lt. Gov. Daniel Mongiardo, 49 percent to 39 percent.