The only reason Newt is supporting Trump is because he knows how an already proven corrupt, incompetent, habitually lying, and weak/dishonest politician (aka, Hillary) would hurt this country and the Supreme Court if she wins the presidency.
As far as your belief that Trump is "unfit & unstable" then you've apparently lost sight of the tactics of the self-centered moron we have in office now. This is not the day and age of putting "gentlemen" in the White House who'll take the high road over personal brand-building or looking bad. Obama was the most unqualified candidate ever....until Trump. The difference is, Trump is a business genius, non-racist, a great family man (Obama's only admirable trait) a fabulous & diverse employer, a decent human being, and a very clear thinker (even if speaking his mind a bit too often shows otherwise).
People all too readily dismiss a brilliant politician like Newt, and they forget what they're criticizing. They say Trump has "no experience". So, would these same people want Hillary-type experience leading us, with nothing but failures and death from top to bottom? Think about it. If Trump somehow wins, he's not gonna be a typical president---and he doesn't have to be. He'll run the show like a CEO, and you'll see a very qualified VP actually work for a living for the first time in history. He'll surround himself with great minds like Newt. Our country will finally change for the better, and racism will finally start to disappear.
Amazingly, Hillary will likely win however, which will go to show how stupid and weak a country we've become overall. And we'll deserve every bit of what we get, with no one to blame but ourselves.
But wouldn't it be GREAT to wake up every day looking at the Internet and TV to see what Trump's hyper-active mind has come up with or what he's doing today!? Soooo refreshing. Or would you prefer seeing a different colored fugly pantsuit every freaking day with a witch's scratchy voice and a very creepy "husband" standing nearby....