Donald Trump is a “ranting lunatic” who has “mental gaffes of his own,” sports commentator Bob Costas said on Real Time with Bill Maher Friday. Costas, who in 2022 gave a scathing takedown of Trump’s decision to host a Saudi golf tournament, appeared on Maher’s show and was asked about the recent developments in Joe Biden’s documents probe. Specifically, the CNN commentator was asked about the special counsel report that cast Biden as an elderly man with severe memory problems keeping him from being tried in court. ALSO READ: Alina Habba is persona non grata at her Pennsylvania law school Cost…