Question: The voters of the US state having the most successful American Idol contestant from this season have leaned republican since what year?

full_context: Document 1: American Idol: The show itself is popular in the Southern United States, with households in the Southeastern United States 10% more likely to watch American Idol during the eighth season in 2009, and those in the East Central region, such as Kentucky, were 16 percent more likely to tune into the series. Data from Nielsen SoundScan, a music-sales tracking service, showed that of the 47 million CDs sold by Idol contestants through January 2010, 85 percent were by contestants with ties to the American South.
Document 2: American Idol: Chris Daughtry's performance of Fuel's "Hemorrhage (In My Hands)" on the show was widely praised and led to an invitation to join the band as Fuel's new lead singer, an invitation he declined. His performance of Live's version of "I Walk the Line" was well received by the judges but later criticized in some quarters for not crediting the arrangement to Live. He was eliminated at the top four in a shocking result.
Document 3: American Idol: Despite being eliminated earlier in the season, Chris Daughtry (as lead of the band Daughtry) became the most successful recording artist from this season. Other contestants, such as Hicks, McPhee, Bucky Covington, Mandisa, Kellie Pickler, and Elliott Yamin have had varying levels of success.
Document 4: North Carolina: In 2012, the state elected a Republican Governor (Pat McCrory) and Lieutenant Governor (Dan Forest) for the first time in more than two decades, while also giving the Republicans veto-proof majorities in both the State House of Representatives and the State Senate. Several U.S. House of Representatives seats also flipped control, with the Republicans holding nine seats to the Democrats' four. In the 2014 mid-term elections, Republican David Rouzer won the state's Seventh Congressional District seat, increasing the congressional delegation party split to 10-3 in favor of the GOP.
Document 5: North Carolina: As in the rest of the former Confederacy, North Carolina had become a one-party state, dominated by the Democratic Party. Impoverished by the Civil War, the state continued with an economy based on tobacco, cotton and agriculture. Towns and cities remained few in the east. A major industrial base emerged in the late 19th century in the western counties of the Piedmont, based on cotton mills established at the fall line. Railroads were built to connect the new industrializing cities. The state was the site of the first successful controlled, powered and sustained heavier-than-air flight, by the Wright brothers, near Kitty Hawk on December 17, 1903. In the first half of the 20th century, many African Americans left the state to go North for better opportunities, in the Great Migration. Their departure changed the demographic characteristics of many areas.
Document 6: American Idol: Since the show's inception in 2002, ten of the fourteen Idol winners, including its first five, have come from the Southern United States. A large number of other notable finalists during the series' run have also hailed from the American South, including Clay Aiken, Kellie Pickler, and Chris Daughtry, who are all from North Carolina. In 2012, an analysis of the 131 contestants who have appeared in the finals of all seasons of the show up to that point found that 48% have some connection to the Southern United States.
Document 7: American Idol: Theories given for the success of Southerners on Idol have been: more versatility with musical genres, as the Southern U.S. is home to several music genre scenes; not having as many opportunities to break into the pop music business; text-voting due to the South having the highest percentage of cell-phone only households; and the strong heritage of music and singing, which is notable in the Bible Belt, where it is in church that many people get their start in public singing. Others also suggest that the Southern character of these contestants appeal to the South, as well as local pride. According to season five winner Taylor Hicks, who is from the state of Alabama, "People in the South have a lot of pride ... So, they're adamant about supporting the contestants who do well from their state or region."
Document 8: Oklahoma: After the 1948 election, the state turned firmly Republican. Although registered Republicans were a minority in the state until 2015, starting in 1952, Oklahoma has been carried by Republican presidential candidates in all but one election (1964). This is not to say that every election has been a landslide for Republicans: Jimmy Carter lost the state by less than 1.5% in 1976, while Michael Dukakis and Bill Clinton both won 40% or more of the state's popular vote in 1988 and 1996 respectively. Al Gore in 2000, though, was the last Democrat to even win any counties in the state. Oklahoma was the only state where Barack Obama failed to carry any of its counties in both 2008 and 2012.
Document 9: American Idol: Ruben Studdard emerged as the winner, beating Clay Aiken by a small margin. Out of a total of 24 million votes, Studdard finished just 134,000 votes ahead of Aiken. This slim margin of victory was controversial due to the large number of calls that failed to get through. In an interview prior to season five, executive producer Nigel Lythgoe indicated that Aiken had led the fan voting from the wildcard week onward until the finale.
Document 10: American Idol: In what was to become a tradition, Clarkson performed the coronation song during the finale, and released the song immediately after the season ended. The single, "A Moment Like This", went on to break a 38-year-old record held by The Beatles for the biggest leap to number one on the Billboard Hot 100. Guarini did not release any song immediately after the show and remains the only runner-up not to do so. Both Clarkson and Guarini made a musical film, From Justin to Kelly, which was released in 2003 but was widely panned. Clarkson has since become the most successful Idol contestant internationally, with worldwide album sales of more than 23 million.
Document 11: North Carolina: North Carolina's party loyalties have undergone a series of important shifts in the last few years: While the 2010 midterms saw Tar Heel voters elect a bicameral Republican majority legislature for the first time in over a century, North Carolina has also become a Southern swing state in presidential races. Since Southern Democrat Jimmy Carter's comfortable victory in the state in 1976, the state had consistently leaned Republican in presidential elections until Democrat Barack Obama narrowly won the state in 2008. In the 1990s, Democrat Bill Clinton came within a point of winning the state in 1992 and also only narrowly lost the state in 1996. In the early 2000s, Republican George W. Bush easily won the state by over 12 points, but by 2008, demographic shifts, population growth, and increased liberalization in heavily populated areas such as the Research Triangle, Charlotte, Greensboro, Winston-Salem, Fayetteville, and Asheville, propelled Barack Obama to victory in North Carolina, the first Democrat to win the state since 1976. In 2012, North Carolina was again considered a competitive swing state, with the Democrats even holding their 2012 Democratic National Convention in Charlotte. However, Republican Mitt Romney ultimately eked out a 2-point win in North Carolina, the only 2012 swing state that Obama lost, and one of only two states (along with Indiana) to flip from Obama in 2008 to the GOP in 2012.
Document 12: American Idol: Both finalists found success after the show, but Aiken out-performed Studdard's coronation song "Flying Without Wings" with his single release from the show "This Is the Night", as well as in their subsequent album releases. The fourth-place finisher Josh Gracin also enjoyed some success as a country singer.
Document 13: American Idol: American Idol is an American singing competition television series created by Simon Fuller, produced by FremantleMedia North America and 19 Entertainment, and distributed by FremantleMedia North America. It began airing on Fox on June 11, 2002, and ended its first - run on April 7, 2016. On March 11, 2018, the show will make its debut on ABC. It started off as an addition to the Idols format based on the British series Pop Idol, and became one of the most successful shows in the history of American television. The concept of the series involves discovering recording stars from unsigned singing talents, with the winner determined by the viewers in America through telephones, Internet, and SMS text voting. Winners chosen by viewers in its fifteen seasons were Kelly Clarkson, Ruben Studdard, Fantasia, Carrie Underwood, Taylor Hicks, Jordin Sparks, David Cook, Kris Allen, Lee DeWyze, Scotty McCreery, Phillip Phillips, Candice Glover, Caleb Johnson, Nick Fradiani, and Trent Harmon.
Document 14: American Idol: As one of the most successful shows on U.S. television history, American Idol has a strong impact not just on television, but also in the wider world of entertainment. It helped create a number of highly successful recording artists, such as Kelly Clarkson, Daughtry and Carrie Underwood, as well as others of varying notability.
Document 15: 2016 United States presidential election in North Carolina: The 2016 United States presidential election in North Carolina was won by Republican nominee Donald Trump on November 8, 2016, as part of the 2016 general election. North Carolina voters chose 15 electors to represent them in the Electoral College via a popular vote.
ground_truth: 1976
sub_queries: Who was the most successful artist from this season? Answer: Chris Daughtry
What state is American Idol contestant Chris Daughtry from? Answer: North Carolina
North Carolina voters have leaned republican since what year? Answer: 1976