Brian Nieves is a Republican Missouri State Senator from Washington who represents the 26th district, which covers Franklin County, Warren County, and part of St.Louis County. He is the former majority whip in the Missouri House of Representatives.
Nieves criticized by the Southern Poverty Law Center for extremist views and behavior, including expressing support for a “Patriot uprising,” 'English only' legislation, appearances in a film produced by Alex Jones, an individual who believes the federal government was involved with the Oklahoma City Bombings, membership in an anti-immigrant group called State Legislators for Legal Immigration, SLII, and an incident in which the State Senator allegedly pulled a gun on an opposing campaign staffer. Source: SPLC: Nieves “Extremist Views” Attacking the Constitution Eli Yokley. Southern Poverty Law Center. March 13, 2001.
His Missouri State Senate Home Page identifies him as a member of the Tea Party and as being supported by the Republican Liberty Caucus, which bills itself as the "small government, liberty-defending wing of the Republican Party." Resumably there is at least one other wing of the GOP that does not fit that description. Nieves might says he favors "small government" and "liberty" but he wants a State powerful enough to regulate the reproductive rights of women.