He is professor of History on John Paul II Catholic University of Lublin.
In 1976-1980 and 1985-1989 he was deputy of Sejm. In 1991-1993, 2005-2007 senator. In 2007 elected from list of Law and Justice. Bender has been accused of antisemitism and Holocaust denial after he said that Auschwitz was "not a death camp" but a "labour camp". He later said his remarks were taken out of context. He has also spoken out in defense of Dariusz Ratajczak.