McCain-Lieberman Wasn't Legally Viable

[Landslide Lyndon]

I thought that the candidates can choose whomever they like as their vice-president.
This is the first time I hear that there are laws about him being member of the same party as the presidential candidate.

You'd think that after all the talk about Kerry and McCain in 2004 and McCain-Lieberman or Obama-Hagel last year, somebody would have noticed that.