I've seen a couple of stories proclaiming that Chris Christie is lining up to be Trumps running mate. I'm surprised by this. I have some doubts about this as a practical course of action.
Donald Trump's tendency to come off as brash, and abrasive is one of his biggest negative attributes with Republican voters. I'm not as prone to place style over substance.
The majority of Republican voters do place a high value on the style and presentation of ideas. Conservatives like a more refined way of doing things. Donald Trump comes off as a stereotypical New Yorker. If you are from the North East United States or the West Coast, that probably isn't a problem for you. If you are from the Midwest, South or West, New Yorker ways don't generate warm fuzzy feelings.
Chris Christie is from New Jersey. In flyover country, New Jersey is Gomorrah to New York's Sodom. If Trump was to pair up with Christie his ticket would lose appeal for many traditional Republicans. That's not an argument based on what kind of job Christie would do, its a style over substance evaluation. Republican voters are likely to make that kind of evaluation.
Who should Trump pick as his running mate?
From a purely electability point of view, it should be someone who helps balance out Trump's negatives. What are Trump's negatives? Despite the media's bombardment on the subject, it isn't the ideas or policies that Trump advocates. Trump's biggest negative with Republican voters is his abrasiveness. Right behind that is a perception that Trump might not be as strong in the religious value department as some would like.
To balance that out, Trump should pick a VP that is viewed in a positive manor by the evangelical voter and as a gentleman by the social conservative. The VP has to fit in one other way as well. The VP has to be a political outsider who is adamantly against the status quo, because that is how Trump has fashioned his campaign. Preferably, this person would also bring a following of voters in the general election.
The most practical name that comes to my mind is Dr. Ben Carson. Dr. Carson comes across in a respectable manor. He is known to have a strong life long marriage. He is viewed as religiously conservative. He was speaking out against the evils of political correctness years before he ran for president. He also ran as an anti-establishment candidate. As his own candidate he was pulling 3-5% of primary voters. That isn't too bad considering the number of candidates that started the race. Along with that, Ben Carson is black.
As a group blacks have a strong sense of racial identity. Blacks vote for blacks. Between 13% and 15% of the total population is black. If Trump wins the nomination some establishment republicans have vowed to go over to Hillary. Nobody has solid figure on that number but the black voter will more than make up for it.
Chris Christie doesn't bring as much to the ticket as someone like Carson. Christie may very well end up with a cabinet level job, but it would be a mistake to put him on the ticket, there are better choices that will resonate with voters in the general election.