They haven't. In fact, they have expanded the deduction.
Here is the language from the Kansas Department of Revenue:
For the tax years commencing on and after January 1, 2015, and ending before
January 1, 2018, the Kansas itemized deduction of an individual means the following
deductions from federal adjusted gross income, other than federal deductions for
personal exemptions, as provided in the federal internal revenue code with the
modifications specified in this section: (A) 100% of charitable contributions that
qualify as charitable contributions allowable as deductions in section 170 of the federal
internal revenue code; source Kansas Itemized
Deductions
