On the same day that Walmart’s PR efforts got a huge boost from First Lady Michelle Obama’s endorsement of the company’s plan to sell healthier foods, 25 people affiliated with the group Walmart-Free D.C. peacefully gathered to protest the arrival of four — possibly even five — outlets of the retail behemoth in the District. But instead of demonstrating at one of the possible Walmart locations or making their opinions known to members of the D.C. Council, the protesters descended on the Woodley Park home of Dick Knapp, an executive at Foulger-Pratt, the company that is set to develop the Georgia Avenue Walmart.