MSNBC's Ari Melber hosts "The Beat" on Thursday, October 20th and reports on the midterms as campaign clashes escalate and President Obama hits the campaign trail and new polling shows a GOP edge in the House. Plus, Trump hiring a law firm to handle his forthcoming Jan. 6 subpoena as the committee huddles to finalize details. Fmr. DNC Chair Howard Dean, Fmr. RNC Chair Michael Steele and Harvard professor Dr. Erica Chenoweth join.