No easy answers.  But one thing you can do is to go to the congressional websites to see what bills are introduced and who votes for them.  For example, there are bills for impeaching president Trump. Anyone who votes for those is an instant traitor.  In the case of Al Green's bill introduced in January 2018, anyone voting to Nay on tabling it, is someone to look at more closely.  Here are the names: http://clerk.house.gov/evs/2018/roll035.xml  ---- NAYS    66 --- Adams Barragán Bass Beatty Brady (PA) Butterfield Capuano Carson (IN) Clark (MA) Clarke (NY) Clay Cohen DeSaulnier Doggett Ellison Engel Espaillat Evans Frankel (FL) Garamendi Gomez Green, Al Grijalva Gutiérrez Hastings Higgins (NY) Huffman Jackson Lee Jayapal Jeffries Johnson, E. B. Kelly (IL) Lawrence Lee Lewis (GA) Lieu, Ted Lowenthal McCollum McGovern McNerney Moore Moulton Napolitano Norcross Pallone Pascrell Payne Pingree Pocan Polis Raskin Richmond Rush Schakowsky Scott, David Serrano Sherman Thompson (MS) Titus Vargas Vela Velázquez Walz Waters, Maxine Watson Coleman Wilson (FL) More information on congress.gov. Hope it helps.