The traditional use of the word reactionary was to mean advocacy of, return to a former state of being or the rolling back of reform.

The term reactionary, has at times been used as a pejorative or snarl word.

Reactionary as part of the American Political Spectrum

There are many ways to study the spectrum of political thought, and one of the oldest was as a single axis of change or reform.  Many of the terms we use today seem to have originated with this kind of single-axis description and can be somewhat confusing when separated from it.

Radical > Progressive > Moderate > Conservative > Reactionary

The normalization of reactionary policy within American Conservatism has shifted the use of these terms.  Trump's phrase "Make America Great Again" or Reagan's "let's make America great again" are undeniably reactionary, in that they assert that America was greater before reforms, and will be greater if those reforms are eliminated.  Many Americans no longer accept the inevitability of Liberalism's progress, or even the necessity to adhere to liberal constitutional norms.  Moderates and even Progressives are finding themselves less able to institute reforms and more often in the traditionally conservative position of resisting change, the rollback of those reforms.