Definition of "obstructionist"

"And you, sir, have lived an unimaginative obstructionist and never can hope now to emerge from it."

1913, Arthur Conan Doyle, “(please specify the page)”, in The Poison Belt […], London; New York, N.Y.: Hodder and Stoughton

The obstructionists didn't have their own plan, but they counted, successfully, on delay to frustrate any alternative.

2020 June 23, John Bolton, The Room Where It Happened: A White House Memoir, New York, N.Y.: Simon & Schuster, page 395