AC

What's one way to blunt the effects of outside interest groups on politics? Ban them. That's what Republican Sen. Scott Brown and Democratic challenger Elizabeth Warren did in their Massachusetts Senate race. The two candidates struck a unique deal in January (pdf) to penalize one another if any outside group bought advertising to influence their race--and it has worked. Maybe too well. Consultants and political observers now question whether the ban has come at an electoral price. Brown was the driving force behind the agreement, dubbed the "People's Pledge." After weathering a negative special election campaign against Martha Coakley in 2010 and then facing attacks from the League of Conservation Voters and the League of Women Voters in his race against Warren in 2011, Brown lobbied hard for the arrangement. When Warren, a Harvard Law professor and consumer advocate, agreed in Jan. 2012 to a pact requiring each candidate to pay penalties to charity if outside groups...