Part of our system of checks and balances includes giving the Legislature the ability to override vetoes the governor makes to legislation the Missouri General Assembly sends to him. If a bill is vetoed during the regular legislative session, lawmakers can opt to override the veto while still in session; otherwise, 10 days are set aside in September for the Missouri Senate and House of Representatives to come back to the Capitol and consider any of the vetoes made after regular session adjourns in May.
When the governor vetoes any piece of legislation, he normally includes a veto letter, which spells out exactly why he made his decision. Sometimes, a veto is made simply because there was a spelling or grammatical error that changes the meaning of a bill. Sometimes, it may be over a certain amendment added to the original bill with which he disagrees. Other times, it is because the governor does not like any aspect of the legislation. These are all his legal prerogatives.