SEASON PREMIERE: It’s back. And for this new season of covering politics on the fly in a first-draft insiders’ view of history, the lineup is tweaked a bit yet again. The Circus began as a troika, with John Heilemann, Mark McKinnon and Mark Halperin. When Halperin was dismissed from both The Circus and MSNBC because of charges of sexual harassment dating back to his days at ABC News, The Circus replaced him with another roving reporter, Alex Wagner. And for this season, The Circus adds another contributor – and, like Heilemann, a very familiar face from MSNBC. Beginning tonight, former Republican campaign advisor, and former Republican, Steve Schmidt joins the roster of contributors.