Candidates and their strategists always look for a way to get inside the head of the voter, especially one who is undecided or has specific negative opinions of a candidate.
A candidate cannot win if his message isn't delivered in a way that connects and says, "I share your pain."
One tool that has been used to perfect candidate messaging is dial-testing -- the continuous gathering of real-time feedback from a candidate's speech or debate performance.
Focus groups are given hand-held devices to measure -- on a scale of 0 to 100 -- agreement or disagreement with candidate statements. Crunched, those numbers give strategists data on how their candidates' messages are connecting with voters.
"You are recording literally in the moment people's responses to a speech," said Rich Thau, president of Presentation Testing, who has dial-tested eight of the presidential debates this year. "It is a way to get a level of audience responsiveness that would be impossible in a traditional focus group."
Dial-testing has been used by ad agencies for years: Those cool Super Bowl beer commercials aren't created in a vacuum; they are tested inside and out before they hit the tube. The same theory applies to campaigns.
Two candidates that have dial-tested consistently high in their party's presidential debates are former Arkansas Gov. Mike Huckabee and New York Sen. Hillary Clinton. Illinois Sen. Barack Obama, former New York Mayor Rudy Giuliani and former Massachusetts Gov. Mitt Romney also have scored well.
Two who have not are Rep. Ron Paul of Texas and former Alaska Sen. Mike Gravel. Also near the bottom: Sens. Joe Biden, John McCain, Chris Dodd and Sam Brownback.
Thau says these long-tenured senators suffer from "senator-itis" -- an inability to get to the essence of any issue in less than 10 minutes. "They refuse to accept one of the primary tenets of political messaging, which is if you are explaining you are losing."
Huckabee's messaging is effective, says Thau. "His verbiage is incredibly impactful and his impact is not just among Republicans but independents and Democrats as well. He is tapping into a vein of concern about economic insecurity that a lot of his fellow Republicans are missing."
Steve McMahon, a Democrat strategist and ad man, says he's not surprised by Huckabee's messaging ability: "He truly is a compassionate conservative that offers up red-meat issues and answers."
As for Hillary Clinton, McMahon says "she simply does not make mistakes. She articulates herself more like an executive than like a legislator. Her answers to questions are clear, unambiguous and strong."
McMahon says the key to effective messaging is to summarize your point, then to offer the rationale. "The data that dial-testing provides helps candidates get there. It also helps insiders get inside a voter's head."
With the 2008 presidential election considered to be a wide-open affair, each party knows that swing voters are the key to winning. And the only way to win those voters is to get inside their heads to find out what phrase, word, delivery style or image will help capture their votes.
Voters, however, are funny. It's not always what you tell them that matters; it's what they hear.