With just under one month left before the June 1 special election to replace former Republican Rep. William Janklow in South Dakota, the contest between Democrat Stephanie Herseth and Republican Larry Diedrich is starting to hit its stride.

Herseth -- the 2002 Democratic nominee who held former four-term Gov. Janklow to 53 percent and the better known of the two candidates -- started the race with tremendous name identification and high positives, making her the virtual incumbent. Diedrich, meanwhile, had not gotten much traction from a series of positive ads run by both his campaign and the National Republican Congressional Campaign. A late March poll showed Herseth leading the contest by 16 points. But in running its first contrast ad this week, the Diedrich campaign has shown it intends to fight against letting the Herseth campaign dictate the race.

With Diedrich 16 points behind a well-known candidate, conventional political tactics would suggest he go on the offensive. But in a special election in this already saturated media market -- South Dakota voters have been awash in political ads since 2001,

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