Twitter's bylaws contain anti-takeover provisions which would make a hostile takeover difficult. In their latest 10K they list these provisions which includes "authorizing 'blank check' preferred stock, which could be issued by our board of directors without stockholder approval and may contain
voting, liquidation, dividend and other rights superior to our common stock". So if Musk attempted to get shareholders to vote out the board, the board could issue preferred stock with voting rights which could dilute Musk's votes.
Link: https://d18rn0p25nwr6d.cloudfront.net/CIK-0001418091/947c0c3...