Kansas Governor Sam Brownback has reversed an order than had been on the books for 8 years which barred discrimination based on sexual orientation or gender identity but, as Ian Millhiser at ThinkProgress points out, if a state employee is fired for either reason the state will probably find itself on the losing end of a federal lawsuit.
The Supreme Court implied as much in 2013 when the Defense of Marriage Act was struck down.
The Constitution forbids states from denying any person “the equal protection of the laws.” In the gay rights context, the Supreme Court explained most recently in its 2013 decision striking down the anti-gay Defense of Marriage Act (DOMA), “[t]he Constitution’s guarantee of equality ‘must at the very least mean that a bare congressional desire to harm a politically unpopular group cannot” justify disparate treatment of that group.'”
It stands to reason that if the Equal Protection Clause of the Fourteenth Amendment renders same-sex marriage bans unconstitutional, it would also be unconstitutional to fire a state employee based on their sexual orientation or gender identity.
It's impossible to say with any certainty which way today's Supreme Court will rule on any issue, but I have a hunch that this theory will be tested sooner rather than later and Kansas will find itself in the headlines for unfortunate reasons again.