Former President Donald Trump is seeing his campaign dragged down by his choice of running mate, explained Fordham University political science professor Christina Greer on Monday’s edition of MSNBC’s “The Beat.” This comes after the Trump campaign has endured weeks of attacks that Sen. J.D. Vance (R-OH), who has called for total abortion bans and said the Democratic Party is run by “childless cat ladies,” is “weird” — a criticism Vance himself has been forced to address. “This is how Trump is starting the week,” said anchor Ari Melber. “A lot of those quotes [on his campaign] were from people…