So did Travis, the way the shareholders and board got around that was by threatening expensive and public lawsuits.
If you take a lot of money from rich people you're never gonna be above their power.
Pretty sure Travis didn't. IIRC he had the single largest bloc of voting rights (~18%), but that can still be overruled.
~58% (Zuckerberg's share percentage) can't be ousted no matter how the other voting shares vote.
He could be sued out of excess (exceeding his proportion of shares) voting rights by beneficiary action. This is a public company, remember your fiduciary and beneficiary rights.