Eye surgeon Rand Paul held a whopping 19-point lead over Secretary of State Trey Grayson in a new poll on Kentucky’s GOP Senate primary. Paul, the son of Rep. Ron Paul (R-Texas), led Grayson 44 percent to 25 percent, according to the survey of 478 likely Republican primary voters conducted by Public Policy Polling, a Democratic firm. The poll, taken Dec. 18-21, had a 4.5-point margin of error.Grayson was the early favorite in the race to replace retiring Sen. Jim Bunning (R), and he has the support of the state and national GOP establishment, led by Senate Minority Leader Mitch McConnell (R-Ky.). But Paul has gained momentum in recent months with the help of strong fundraising and an anti-establishment message.Democrats also have a very competitive primary ahead of what is expected to be a closely fought general election. In the Democratic race, a separate PPP survey of 557 likely primary voters found state Attorney General Jack Conway ahead of Lt. Gov. Daniel Mongiardo, 37 percent to 33 percent. But that result was within the poll’s 4.2-point margin of error.