which source is likely to be the least biased
You have an alias which is overriding the builtin source (fix with unalias source) You have a function which is overriding source (fix with unset -f source) You are somehow not using bash (although your bang line would suggest you are). source is not POSIX. Using source on dash does not work, only . works.
Which TV/Video News Sources are the Most Reliable and Least Biased ...