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Today is the big one, the Super Tuesday of the primary season, with six states holding primaries across the country, including Arkansas, Georgia, Idaho, Kentucky, Oregon,and Pennsylvania.

WHO'S ON THE BALLOT?Today's key race features the senate minority leader pummeling a tea party challenger in Kentucky, setting up perhaps the marquee matchup of 2014. A pediatric neurosurgeon is trying to get the GOP nomination in Oregon after a weekend of stories about her personal life. Children and grandchildren of politicians are trying to send another generation to elected office. And a Clinton in-law is eager to get her old House seat back. That's just a taste of the variety of choices voters have in the six states voting today.

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Here's the top primary races being held today and nine reasons why they matter:

THE START OF A REAL BLUEGRASS BRAWL: The Kentucky GOP Senate primary is tonight's marquee race although polls show Senate Minority Leader Mitch McConnell beating his tea party challenger Matt Bevin by a wide margin. The most recent survey, an NBC News/Marist poll from earlier this month had McConnell leading by 32 points. And how big (or small) the margin is will be important to look at as well. WHY IT MATTERS: McConnell was the number one target for the tea party, but it looks like they have fell short-well short-in this fight. The race was supposed to be a closer battle coming into primary season with McConnell's unpopularity and Bevin's significant personal finances, but Bevin was a flawed candidate that made serious campaign trail errors and with no political experience was just not up to the challenge. Bevin did have money and national political groups like the Senate Conservatives Fund and the Madison Project backing his candidacy, but it didn't matter as the campaign mistakes and other errors proved too much to topple a giant. This race is still important because as soon as it is over it marks the official start to the general election in the Bluegrass State. McConnell vs. his Democratic opponent, Secretary of State Alison Lundergan Grimes will be the most closely watched race this cycle. In that same NBC News/Marist poll the McConnell vs. Grimes face off shows the 35-year-old ahead of the congressional leader by 9 points. The race could determine control of the Senate and will be a closely watched brawl to the very end.

A SEVEN-WAY BATTLE IN GEORGIA: Tonight, seven Republicans will vie to oppose Democrat Michelle Nunn, who could be a bright spot for Democrats this cycle. The top contenders are David Perdue, the cousin of former Gov. Sonny Perdue and the former CEO of Dollar General; Karen Handel, the former Georgia secretary of state who's backed by conservatives including Sarah Palin, Arizona Gov. Jan Brewer, and blogger/commentator Erick Erickson; and U.S. Reps. Jack Kingston, Phil Gingrey, and Paul Broun. With none of them likely to gather over 50 percent of the vote Tuesday night, the GOP primary will almost certainly head to a July 22 runoff. Polls have shown Perdue leading, with Kingston and Handel as the other top contenders. WHY IT MATTERS: Nunn, the former CEO of the George H.W. Bush-founded Points of Light Foundation and the daughter of former Georgia Democratic Sen. Sam Nunn, is a strong candidate for Democrats in an unexpected state, and Georgia could be an oasis for the party in an otherwise barren 2014 Senate landscape. Despite Georgia's deep red leanings in recent years, polls have shown her narrowly beating the Republicans in the field. Perdue brings the most significant outside money behind him, while Handel, with her endorsements, brings tea party bona fides. Whoever advances tonight, a competitive general-election lies ahead.

POLITICAL OFFSPRING TAKE A BITE OUT OF THE PEACHTREE STATE: For Democrats in Georgia, 2014 is all about turning back the clock. Former U.S. president and Georgia governor Jimmy Carter's grandson state Sen. Jason Carter is running to follow in his grandfather's footsteps, challenging sitting Republican Gov. Nathan Deal. Michelle Nunn is running to fill her father's shoes, hoping to replace retiring GOP Sen. Saxby Chambliss. Perhaps surprisingly given Georgia's strongly Republican voting patterns in recent years, both of them are competitive: Multiple polls show Nunn leading her GOP opponents, and two major surveys this month from the Atlanta Journal-Constitution and NBC News/Marist have shown Carter trailing by four and 10 percentage points, respectively. Tonight, Nunn will almost certainly advance, and Carter certainly will: He's the only qualified Democratic candidate for governor. WHY THEY MATTER: Democrats have talked about a Southern resurgence in the Obama era, and while they've made gains in Virginia and North Carolina, Republicans have maintained a stronghold in the conservative Deep South. Georgia had a Democratic senator and a Democratic governor as recently as 2003, when Roy Barnes governed the state and Max Cleland represented it in the Senate. Nunn and Carter are running competitive campaigns now, but they'll have to navigate issues of health care, gun control, and President Obama's unpopularity if they're to pull off the unexpected and turn a Deep-South state blue in 2014.

RAGE AGAINST THE (CLINTON) MACHINE IN PENNSYLVANIA: What should have been a virtual lockdown in the thirteenth congressional district Democratic primary for former Congresswoman Marjorie Margolies, who just happens to be Chelsea Clinton's mother-in-law, has become a competitive four-way race as Rep. Allyson Schwartz leaves her seat to run for governor. Margolies, who has struggled to connect with voters, faces strong competition from opponent Brendan Boyle, a state legislator whose campaign focuses on the middle class. The brash yet highly popular State Senator Daylin Leach is also a force to contend with, and Valerie Arkoosh, a practicing obstetric anesthesiologist who spent time working on Obamacare policy, has built her campaign on the success of the healthcare bill. WHY IT MATTERS: This primary race has been called a "fight for the soul of the Democratic party." Why has the highly-connected Margolies, who has had both Bill and Hillary Clinton join the campaign trail-as well as a last minute robo-call from the former president-not been a consistent front-runner? It may come down to two ads in the district, which really show the differences between Margolies and Boyle. One, for Margolies, features Bill Clinton speaking about his longtime ally. Boyle's ad shows the image of a man - the candidate's Irish immigrant father - sweeping the platform at a Philadelphia train station, and tells his "American Dream" story. A win for Boyle, who has raised the least money of the four candidates but boasts a strong grassroots operation, could possibly set the tone for 2016. Boyle, 37, is the youngest candidate in the race by 15 years, and Margolies, at 71, is doing well with older voters who remember her time in the House in the early 1990s. Will the Clintons have coattails?

RACE TO REPLACE THE COUNTRY'S MOST VULNERABLE GOV: The Democratic primary to try and replace the most vulnerable governor in the country, Pennsylvania's Tom Corbett has been a four-way fight, but now it looks like this is businessman Tom Wolf's to lose. Wolf is up against Congresswoman Allyson Schwartz who started this race with the momentum. Besides Wolf and Schwartz, State Treasurer Rob McCord and Katie McGinty, an environmental adviser during the Clinton administration are on the ballot. WHY IT MATTERS: Wolf is leading in state polls, although he was practically unknown when the race started. He heads one of the country's largest manufacturers of kitchen and bathroom cabinets and has poured most of the over $14 million he has raised into television advertising trying to introduce himself to Keystone state voters and bring up his name recognition. Corbett has already been focusing his fire on Wolf while Wolf's Democratic opponents have attacked him for how much money he has spent and Schwartz, who ran embracing Obamacare, has hit Wolf for lack of political experience.

WILL A STRANGE TALE IN OREGON CHANGE GOP FATE?: It has been quite a few days in the GOP primary race in Oregon. Revelations came to light over the weekend that an ex-boyfriend of Dr. Monica Wehby -a renowned pediatric neurosurgeon who was the first woman to graduate from UCLA's neurosurgery program-called the police last April and claimed she was "stalking him," although he helped fund a super PAC attacking her opponent, state representative Jason Conger. Andrew Miller, a lumber executive, says he still backs Wehby and he "regrets" ever getting the police involved. Before the news surfaced, first reported by Politico, Wehby seemed poised for victory. But, just the night before the primary The Oregonian reported on the existence of a 2007 police report, which details Wehby's ex-husband's allegations of harassment while they were going through a divorce. Wehby's now ex-husband, Jim Grant, also called 9-11 after this altercation with her. Also Monday night, KGW, the NBC affiliate in Portland, revealed another police report Grant filed in 2009. This time over a custody issue. WHY IT MATTERS: These are strange tales, but as Oregon is a vote by mail state it may not have any impact on the primary, although in the last election 55 percent of voters did drop off their ballot in person on election day. If Wehby wins tonight it's likely all three of these incidents will be used against her in the general election against incumbent Democrat Sen. Jeff Merkley. In a Friday debate, Conger said the situation raised questions about her judgment that could be used against her in the general election match up. Wehby is considered a rising star in her party and said in a statement the initial police report and 911 call being released is the "cost of challenging the political status quo." Wehby blames the revelations on politics, noting in a statement she is "deeply saddened that such a personal matter, which bears no relevance to my Senate campaign, has been used as a political weapon to attack my character." Wehby's candidacy has buoyed Republicans who now see Oregon as a possible pick up in their race to gain control of the Senate. She's been backed by Republicans including Mitt Romney, Newt Gingrich, and Dr. Ben Carson, and has campaigned heavily against Obamacare. Conger is seen as the more socially conservative choice and has been backed by Oregon Right to Life and Rick Santorum. Oregon has not elected a Republican in a statewide election since 2002, but because of Merkley's support of the Affordable Care Act in a state that had an especially disastrous roll-out of its state health care exchange, which ultimately failed, he is seen as vulnerable.

AN ESTABLISHMENT VS. TEA PARTY BRAWL, THIS ONE FEATURING MITT ROMNEY: Attorney Bryan Smith, backed by the Club for Growth and FreedomWorks, is trying to topple incumbent Rep. Mike Simpson in the Idaho second congressional district GOP primary. Simpson is backed by the business community, including the Chamber of Commerce. The Chamber has run ads, over $2 million worth, on his behalf including one featuring Mitt Romney. WHY IT MATTERS: Looking into the camera Romney says Simpson deserves support because "the stakes are very high in this election because Washington spending is out of control," stressing he has "seen him in action." This was another tea party vs. establishment fight and although polling is scarce, Club for Growth stopped airing ads in this race last month signaling this may no longer be as competitive as it once looked.

THE OTHERS:

THE ARKANSAS FACE-OFF IN A BATTLE FOR THE SENATE: Sen. Mark Pryor, D-Ark., and Rep. Tom Cotton, R-Ark., are expected to secure their respective party's nominations in the Arkansas Senate primary Tuesday night. The Pryor family name runs deep in Arkansas as Pryor's father held the same Senate seat his son is fighting for and served as the state's governor. Pryor's father also forged a strong alliance with the Clinton family which could help boost Pryor in the general election. Cotton, a first-term Congressman who served in Iraq and Afghanistan, is a conservative rising star and is seen by Republicans as one of their top chances to topple Democrats this year. WHY IT MATTERS: There won't be any surprises when it comes to the Arkansas Senate primary. Pryor and Cotton have a distinct advantage compared to other midterm campaigns this year - neither candidate is facing a tough primary race. Pryor enjoys an unchallenged race as the Democratic incumbent while Cotton had establishment Republicans and tea partiers rally around him early on. This has allowed Pryor and Cotton to stay focused on the general election instead of worrying about contentious primary challenges. Republicans are hoping to pick up a Senate seat in this red state, but recent polls show Pryor ahead less than six months from election day. An NBC News/Marist poll released earlier this month had Pryor up eleven points over Cotton.

WHAT ELSE ARE WE WATCHING?

A COWBOY, A CURMUDGEON, A BIKER, AND A NORMAL GUY WALK INTO AN IDAHO VOTING BOOTH: It wasn't just that brave cat who took on a dog to save a little boy that lit up the Internet last week. The strangest debate of all time also became a viral sensation. Idaho Gov. Butch Otter has a real primary challenge from state. Sen. Russ Fulcher, but in order to debate Otter said all of his challengers must be on stage. So they were joined by Walt Bayes and perennial candidate Harley Brown. Brown, wearing biker gear including leather gloves, defended his tendency to offend with racist jokes saying he is waging war against political correctness: "I'm about as politically correct as your proverbial turd in a punchbowl and I'm proud of it," he said when asked about jokes on his campaign website targeted at African-Americans, Asians, Hispanics, women, Jews, and almost every other possible religion or ethnicity. Bayes, sporting his long white beard, spent most of the debate railing against abortion. Brown may have put it best when he said, "Folks, you have a choice: A cowboy, a curmudgeon, a biker or a normal guy. Take your pick." Not to be lost in all this is a real race between Otter and Fulcher and another establishment vs. tea party primary. There's been scarce polling, but Fulcher has tried to paint Otter as not conservative enough. It's a race Otter told the Spokesman-Review he never saw coming: "Did I ever believe in my life somebody would run at me from the right? No, I didn't."