The duo provided him with prominent, consistent platforms on dueling media for his run for Milwaukee County executive and eventually his successful 2010 campaign for governor.
One manager, who helmed an unsuccessful GOP campaign there, grumbles, "I still have PTSD over them."
The unique dynamic – where a handful of trusted, familiar voices reverberate through car stereos and computer speakers on a daily basis – explains the problem Donald Trump is confronting ahead of Tuesday's presidential primary there.
Last week, they put him through a merciless grilling on their programs, which generated considerable national media attention, especially since Trump admitted to being unwittingly unaware of their vehement resistance to him.
For much of their 17-minute conversation last Tuesday, Sykes soberly chided Trump for his general temperament, for his stubborn refusal to apologize for insults and for acting like an unruly child on a playground.
In Green Bay Jerry Bader on WTAQ 1360 AM / 97.5 FM began his interview by delving directly into some of Trump's ripest controversies – from retweeting an unflattering picture of Heidi Cruz to repeatedly attacking Fox News' Megyn Kelly.
After a combative 25-minute back-and-forth with McKenna, Trump hung up.
Kellyanne Conway, the GOP pollster who is heading a super PAC for Sen. Ted Cruz of Texas, said the string of bumpy talk radio appearances underscored Trump's lack of preparation.
"He's hitting a buzz saw now," Conway said of Trump during Sykes' stinging inquisition. "Charlie was just so calm, so surgical."