It’s easier and more likely than you think.
Speculation is growing that Donald Trump (a) may choose Newt Gingrich as his running mate, and (b) isn’t serious about becoming president and might bow out after being elected (read that story here). This would make Newt Gingrich the next President of the United States if voters are foolish enough to elect the GOP ticket. (And then Gingrich could fill the Vice President vacancy with Sarah Palin, Joni Ernst, or Tom Cotton.)