There will be a shareholder vote, but they only need a majority to approve the sale (assuming their equity shareholder structure is "normal" and voting rights exist for common shareholders). However, the majority of any given public company tends to be owned by institutional asset managers like Blackrock and Vanguard. They owe a fiduciary duty to their customers to act in their best interests, and when a deal offers those shareholders a large margin over the market value of their holdings, it's almost impossible for them to vote against it, even if they wanted.