Bob Mercer agrees that Johnson is making a good call... but says Johnson's job is anything but cushy:
When Johnson received the presidential appointment as U.S. attorney for South Dakota from the Obama administration, there was a big question about his credentials, especially in the wake of predecessors Marty Jackley and Jim McMahon. Johnson has shown, week by week, that he intends to drive home respect for the law on reservations and won’t tolerate physical attacks on law enforcement. There also seems to be emphasis on drug, firearm and federal-benefit enforcement. This tough work is performed by the tribal and federal law agents in the field and by the federal prosecutors in the courthouses. All of them, from Johnson down, face some of the most violent and lawless conditions – beatings with baseball bats as one small example – that we can imagine in South Dakota. Brendan Johnson, on a real-life basis, is in a position to accomplish much, much more for the betterment of South Dakota as U.S. attorney in the next two to three years of the Obama administration, than if he did run for the U.S. Senate — and certainly much, much, much more than if he ran and lost [Bob Mercer, "Our U.S. Attorney, Earning His Pay," Pure Pierre Politics, 2013.05.10].
A U.S. Senate candidate has a great opportunity—and a great responsibility—to lead public conversations and, unlike M. Michael Rounds, inform and educate voters. That's now Rick Weiland's job (and step one, Rick is getting a website up!). A U.S. Attorney has a great responsibility to bring justice for all citizens. That's Brendan Johnson's job. Both men have chosen noble callings, and both men have a lot of work to do.
By the way, Josh Verges links to the U.S. Attorney's 2012 report on the hard and ugly things Attorney Johnson fights every day. Sex trafficking, child porn, immigration violations, drugs, fraud, general mayhem... doesn't sound cushy to me.