Voters Tuesday picked U.S. Rep. Joe Sestak as the party's nominee and rejected the 80-year-old Specter in his first Democratic campaign.
Paul had 59 percent of the vote with returns counted from 29 percent of the precincts, compared with 37 percent for Secretary of State Trey Grayson, who was recruited to the race by the state's dominant Republican, U.S. Senate Minority Leader Mitch McConnell.
In another race with national implications, Democrat Mark Critz moved ahead of Republican Tim Burns in a contest to fill out the final few months in the term of the late Rep. John Murtha in Pennsylvania. Each political party invested nearly $1 million in that contest and said the race to succeed the longtime Democratic was something of a bellwether for the fall.
In Kentucky, Grayson had the support of McConnell as well as other establishment figures. But Paul, the son of Rep. Ron Paul, a former presidential contender, countered with endorsements, and the political energy that flowed along with them, from tea party activists, former Alaska Gov. Sarah Palin and Sen. Jim DeMint of South Carolina, a conservative eager to push his party rightward in advance of the broader fall campaign. According to his website, Paul, 47 and an ophthalmologist, is a "career doctor, not a politician."
The race marked the third time that tea party activists have placed their stamp on Republican races.