Question: In the US Senate, in 2012, who replaced an American veterinarian and former politician based in Las Vegas, Nevada?

Context paragraphs:
United States Senate election in Nevada, 2012: The 2012 United States Senate election in Nevada was held on Tuesday, November 6, 2012, alongside 33 other elections to the United States Senate in other states, as well as elections to the United States House of Representatives, and the 2012 United States presidential election.  The primary election was held June 12, 2012.  Incumbent Republican U.S. Senator Dean Heller, who was recently appointed to this seat left vacant by resigning U.S. Senator John Ensign, was narrowly elected to his first full term over Congresswoman Shelley Berkley.

Las Vegas–Paradise, NV MSA: The Las Vegas–Paradise, NV MSA, also known as the Las Vegas–Henderson–Paradise, NV Metropolitan Statistical Area (2013), is in the southern part of the U.S. state of Nevada, coextensive since 2003 with Clark County, Nevada.  A central part of the metropolitan area is the Las Vegas Valley, a 600 sqmi basin that includes the metropolitan area's largest city, Las Vegas as well as the other primary city, Paradise, Nevada.  The area contains the largest concentration of people in the state.  Cities in the metropolitan area include Las Vegas, Henderson, North Las Vegas, and Boulder City.  The metropolitan area is one of the top tourist destinations in the world, drawing over 40 million international and domestic visitors in 2013 with a GMP of US$103.3 billion.

Air Vegas: Air Vegas (IATA: 6V, ICAO: VGA, Call sign: Air Vegas) was an airline with its headquarters on the grounds of the North Las Vegas Air Terminal in North Las Vegas, Nevada.  It operated daily sightseeing flights from Las Vegas to the Grand Canyon.  Prior to moving to the North Las Vegas Airport its main bases were McCarran International Airport (LAS), Las Vegas and Henderson Executive Airport (HND), Las Vegas.

John Ensign: John Eric Ensign (born March 25, 1958) is an American veterinarian and former politician based in Las Vegas, Nevada.  He was a Congressman and United States Senator from Nevada, serving in the latter seat from January 2001 until May 2011.  He resigned amid a Senate Ethics Committee investigation.

Las Vegas Uncork'd: Las Vegas Uncork'd (also referred to as Vegas Uncork'd and Vegas Uncorked) is an annual culinary and wine event in Las Vegas, Nevada.  The concept was developed by the Las Vegas Convention and Visitors Authority, their advertising agency R&R Partners and Las Vegas resort partners who originally considered a number of magazine partners such as Bon Appetit, Food & Wine and Gourmet.  Bon Appetit was selected as the magazine partner after a review with each magazine.  The event was launched in 2007 by the Las Vegas Convention and Visitors Authority, "Bon Appétit" magazine led by Editor-in-Chief Barbara Fairchild and co-creator and Executive Director Rob O'Keefe who led the first five years of development of what Eater.com called "the world's most innovative culinary event".  Las Vegas resort partners over the years include Bellagio, Caesars Palace and Wynn Las Vegas, MGM Grand, Mandalay Bay, The Venetian, Las Vegas and The Palazzo and each year the event features more than 80 celebrated chefs and over 25 events occurring over a spectacular four-day weekend.

Pat Spearman: Patricia Ann "Pat" Spearman (born in 1955) is an American cleric, veteran, and Democratic politician from North Las Vegas, Nevada.  She was elected in November 2012 to the Nevada Senate representing District 1, that is composed of the northern section of North Las Vegas and slivers of neighboring jurisdictions, after defeating incumbent John Jay Lee in the primary, and winning the general election.  Spearman became the first openly lesbian member of the Nevada Legislature.  She was re-elected in November 2016, and serves as co-majority whip since.  Regarded as one of the most liberal members of the Nevada Senate, Spearman has introduced bills that provide equal pay for women, support LGBT rights, and support veterans.  Moreover, she was involved in the process of establishing the Nevada Revenue Plan during the 2015 session.

Las Vegas Valley: The Las Vegas Valley is a major metropolitan area located in the southern part of the U.S. state of Nevada.  The largest urban agglomeration in the state, it is the heart of the Las Vegas–Paradise-Henderson, NV MSA.  The Valley is largely defined by the Las Vegas Valley landform, a 600 sqmi basin area surrounded by mountains to the north, south, east and west of the metropolitan area.  The Valley is home to the three largest incorporated cities in Nevada: Las Vegas, Henderson and North Las Vegas.  Five unincorporated towns governed by the Clark County government are part of the Las Vegas Township and constitute the largest community in the state of Nevada.

Robertson High School: Robertson High School (RHS) is a public senior high school in Las Vegas, New Mexico.  The school is part of the Las Vegas City Schools District in former East Las Vegas.  The building dates from about 1945, when it was known as Las Vegas High School.  The school was renamed Las Vegas Robertson High School in 1958, after the old Las Vegas High School burned down and a new building was constructed.  W. J. Robertson had been the Superintendent of the Las Vegas City Schools since 1941 when he suffered a fatal heart attack on November 26, 1956 at the age of 55.  Mr. Robertson, born in Kansas on November 3, 1901 also served as Principal at Las Vegas High School for many years prior.  The colors of RHS are red and white, their mascot is the Cardinal.  The enrollment currently stands at 607.

Poppermost: Poppermost is an original indie pop rock music band based in Las Vegas, Nevada, United States.  The retro band draws comparisons to The Turtles, The Beach Boys, Harry Nilsson, Simon & Garfunkel, The Beatles, Queen, Elliott Smith, Elvis Costello, The Kinks, Paul McCartney, The Hollies, Traveling Wilburys, Oasis, The Who, Electric Light Orchestra, Wilco, and classic '60s / '70s pop rock radio.  Poppermost has been listed as one of "Our picks for the best bands" by the "Las Vegas Weekly" entertainment magazine, and also received a "Best of Las Vegas 2007" award from the "Las Vegas Review-Journal" newspaper. <ref name="RJ3/25/07">"Best Local R&B Band", "Las Vegas Review-Journal"</ref> Singer/songwriter/multi-instrumentalist, Alex Oliver, and bassist and audio/video/graphics/web designer, Roy Rendahl, both registered with ASCAP, started Poppermost on July 4, 2001.  They have released three full-length albums, and several CD singles and EPs of original music, all recorded at Roy's Trimordial Studio in Las Vegas.  Roy is now mastering their latest recordings too.  Poppermost's influences include: The Beatles, R.E.M., The Beach Boys, Queen, Wilco, Oasis, classic '60s AM and '70s FM, The Who, Carole King, and Burt Bacharach and Hal David.  The Poppermost name originates from the early Beatles' inspirational call and response, John: "Where are we going, lads?"  Paul, George, Ringo: "To the toppermost of the poppermost, Johnny!"

California–Nevada Interstate Maglev: The California–Nevada Interstate Maglev project is a proposed 269 mi Maglev train line from Las Vegas, Nevada to Anaheim, California.  One segment would run from Las Vegas to Primm, Nevada, with proposed service to the Las Vegas area's forthcoming Ivanpah Valley Airport.  The top speed would be 310 mph .  Though $45 million was appropriated in 2005 for the planning phase for the first 40 mi segment, the money was never spent, and was finally reallocated to a highway project in a Las Vegas Airport in June 2010.  The maglev project was not in the 2012 transportation plan under consideration by the Southern California Association of Governments.  Removing it from the plan means that the project cannot receive federal funds, even for studies.  The Southern California Association of Governments did leave a small portion of the route – from Anaheim to Ontario – in their 2012 transportation plan.

Supporting paragraphs: United States Senate election in Nevada, 2012 John Ensign
Answer: Dean Heller