KEY POINTS
  • "The Democrats are trying to make this a referendum on Donald Trump, not his policies, not the issues," a longtime Republican pollster told CNBC on Friday.
  • "I do believe that Joe Biden is ahead, and I do believe the challenges for Donald Trump are significant" heading into next week's GOP convention, added Frank Luntz.
  • Biden has a 7.6 percentage point lead over Trump, based on an average of national polls compiled by RealClearPolitics.

Longtime Republican pollster Frank Luntz on Friday complimented Joe Biden's Democratic National Convention acceptance speech, saying the former vice president succeeded in changing the narrative and toeing the line between both ideological factions of his party. 

"The Democrats are trying to make this a referendum on Donald Trump, not his policies, not the issues, but on Donald Trump himself,"  Luntz said on CNBC's "Squawk Box."