Question: Who was a candidate for the Libertarian Party's 2012 nomination for President of the United States, that unsuccessfully challenged during his tenure, the fourth-ranking Republican leader in the House?

Thomas Jeffery Cole (born April 28, 1949) is the U.S. Representative for Oklahoma 's 4 congressional district , serving since 2003.  He is a member of the Republican Party.  The chairman of the National Republican Congressional Committee (NRCC) from 2006 to 2008, he was, during his tenure, the fourth-ranking Republican leader in the House.  He is a Deputy Majority Whip.  As of 2015, Cole – a member of the Chickasaw Nation – is one of only two registered Native Americans in Congress (the other being fellow Oklahoman Markwayne Mullin). <SEP> Richard Jason Satawk "R. J." Harris (born November 16, 1972) is a United States Army National Guard warrant officer, politician, law student and former Air Traffic Controller.  He was a candidate for the Libertarian Party's 2012 nomination for President of the United States.  In 2010, he unsuccessfully challenged incumbent Tom Cole for the Republican Party nomination in the primary election for Oklahoma's 4th congressional district.  He ran as an independent candidate for the same congressional seat in 2012. <SEP> The 2012 presidential campaign of Gary Johnson, the 29th Governor of New Mexico, was announced on April 21, 2011.  He declared his candidacy for the 2012 Republican Party nomination for President of the United States.  On December 28, 2011, Johnson withdrew his candidacy for the Republican nomination, and declared his candidacy for the 2012 presidential nomination of the Libertarian Party.  The 2012 Libertarian National Convention was held during the first weekend of May 2012.  On May 5, 2012, after promoting his libertarian-oriented political positions to delegates, Johnson received the most votes at the convention and became the official 2012 Libertarian presidential nominee.  On November 6, 2012, Johnson received just under 1% of the popular vote in the general election, amounting to more than 1.2 million votes, more than double what the Barr/Root ticket received in 2008.  This was the most successful result for a third-party presidential candidacy since 2000, and the best in the Libertarian Party's history by vote number at the time.  (Johnson ran again in 2016 and received nearly four times his 2012 vote total.) <SEP> Texas District 8 of the United States House of Representatives is a Congressional district that includes Montgomery County and Walker County.  It includes much of the northern outlying areas of metro Houston.  The current Representative from District 8 is Kevin Brady and has been since 1997.  For the 2014 election cycle Craig McMichael, a veteran of the Marine Corps, and network engineer had challenged and lost to incumbent Kevin Brady in the Republican Primary.  In the 2014 General Election, Brady faced off against the Libertarian Party candidate, Ken Petty of Spring, Texas, who won his nomination in the Libertarian District Convention.  No Democrat ran.  In the 2016 election, the 20-year incumbent was challenged by 3 challengers: Andre Dean, Craig McMichael, and Steve Toth.  As of August 2017, Brady is expected to face Democrat Steven David in the 2018 election as well as Independent candidate Todd Carlton.  David is the first Democrat to challenge Brady since the 2012 election.