Doug Collins is very smart

It seems to be in the Oxford Dictionary.....which is a pretty clear confirmation that it IS a word.

Not really, it is also listed as an improper use elsewhere if you look further or search "is irregardless a word". You will note it is listed as "non standard".
It's just regardless and irregardless is used by people trying to inflate the meaning of regardless. Regardless is without regard and does not require embelishment for intended meaning.

I'm not saying that it's a good choice when constructing a sentence, only that it is a real word.

Try finding a reputable book that uses the word "irregardless" in a context, other than coming from a complete moron.

It's in this book.

So I guess if enough stupid people say it, then it becomes true. No wonder we literally have an illiterate moron in the White House, LOL.