obstructionist

One who systematically blocks or interrupts a process, especially one who attempts to impede passage of legislation by the use of delaying tactics, such as a filibuster.

One who factiously opposes and hinders the action of others; specifically, one who systematically, persistently, and factiously hinders the transaction of business in a legislative assembly; an obstructive; a filibuster.

One who deliberately hinders progress; one who obstructs business, as in a legislative body.

someone who systematically obstructs the actions of others

someone who attempts to impede the progress of legislation

someone who systematically obstructs some action that others want to take