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?

<P0-S0>  He was a candidate for the Libertarian Party's 2012 nomination for President of the United States. <P0-S1>  In 2010, he unsuccessfully challenged incumbent Tom Cole for the Republican Party nomination in the primary election for Oklahoma's 4th congressional district. <P0-S2>  He ran as an independent candidate for the same congressional seat in 2012. <P0-S3> 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. <SEP> <P1-S0>  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. <P1-S1> Thomas Jeffery Cole (born April 28, 1949) is the U.S. Representative for Oklahoma 's 4 congressional district , serving since 2003. <P1-S2>  He is a member of the Republican Party. <P1-S3>  He is a Deputy Majority Whip. <P1-S4>  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> <P2-S0> Texas District 8 of the United States House of Representatives is a Congressional district that includes Montgomery County and Walker County. <P2-S1>  It includes much of the northern outlying areas of metro Houston. <P2-S2>  The current Representative from District 8 is Kevin Brady and has been since 1997. <P2-S3>  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. <P2-S4>  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. <P2-S5>  No Democrat ran. <P2-S6>  In the 2016 election, the 20-year incumbent was challenged by 3 challengers: Andre Dean, Craig McMichael, and Steve Toth. <P2-S7>  As of August 2017, Brady is expected to face Democrat Steven David in the 2018 election as well as Independent candidate Todd Carlton. <P2-S8>  David is the first Democrat to challenge Brady since the 2012 election. <SEP> <P3-S0> The 2012 presidential campaign of Gary Johnson, the 29th Governor of New Mexico, was announced on April 21, 2011. <P3-S1>  He declared his candidacy for the 2012 Republican Party nomination for President of the United States. <P3-S2>  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. <P3-S3>  The 2012 Libertarian National Convention was held during the first weekend of May 2012. <P3-S4>  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. <P3-S5>  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. <P3-S6>  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. <P3-S7>  (Johnson ran again in 2016 and received nearly four times his 2012 vote total.)