Sen. Saxby Chambliss (R-GA) speaks to members of the media after a hearing in November 2012. (Photo by Alex Wong/Getty Images) 
 
 Sen. Saxby Chambliss (R-Ga.), one of the Republicans most vulnerable to a conservative primary challenge, will retire in 2014 rather than seek a third term. 
 
 Chambliss denied in a statement Friday morning that the potential primary was a factor in his decision, saying he was confident he would have won re-election. 
 
 “Instead, this is about frustration, both at a lack of leadership from the White House and at the dearth of meaningful action from Congress, especially on issues that are the foundation of our nation’s economic health," Chambliss said. "The debt-ceiling debacle of 2011 and the recent fiscal-cliff vote showed Congress at its worst and, sadly, I don’t see the legislative gridlock and partisan posturing improving anytime soon." 
 
 The news of Chambliss's retirement was first reported by the Atlanta Journal-Constitution. 
 
 Two Republican House members, Paul Broun and Tom Price, were considering campaigns against Chambliss. Former Georgia Secretary of State Karen Handel was also interested in the race. 
 
 Despite his largely conservative record, Chambliss has attracted conservative ire for his interest in bipartisan compromise. His recent public break with anti-tax advocate Grover Norquist earned him particular scrutiny. He also struggled in the 2008 election, forced into a runoff with Democrat Jim Martin. 
 
 Sen. Lindsey Graham (R-S.C.), another senator vulnerable to a primary challenge, responded with "great sadness and disappointment" to the news of his friend's retirement. 
 
 Given how many big names were already interested in the seat, there will almost certainly be a crowded primary. Polling suggests former presidential candidate Herman Cain would be a strong contender, but he said again Friday that he is not running. 
 
 Democrats are also expressing interest. 
 
 “Georgia will now offer Democrats one of our best pick-up opportunities of the cycle," said Democratic Senatorial Campaign Committee Executive Director Guy Cecil, noting changing demographics and a potentially divisive GOP primary. "This will be a top priority.” Atlanta Mayor Kasim Reed is considered a top Democratic prospect, along with Rep. John Barrow. ||||| Georgia Senator Saxby Chambliss is theoretically very vulnerable to a primary challenger in 2014: it's just a question of whether any of the folks interested in taking him on can run a strong enough campaign to take advantage of that vulnerability. 
 
 Only 38% of Republican primary voters say they want Chambliss to be their nominee next year, compared to 43% who would prefer someone more conservative. But Chambliss stomps most of the people who've shown the most interest in taking him on. He leads Congressman Paul Broun by a 57/14 margin in a head to head, has a 50/22 advantage over Congressman Tom Price, and leads former Secretary of State Karen Handel 52/23. 
 
 By far and away the Republican who would pose the greatest threat to Chambliss in a primary, if he changed his mind about running, is Herman Cain. Cain would lead Chambliss 50-36 in a hypothetical match up. Cain has a 68/20 favorability rating with GOP primary voters, which compares quite favorably to Chambliss' 45/36 approval spread. Other long shot candidates we tested against Chambliss were Allen West, who trails 47/26, and Erick Erickson who trails 51/22. 
 
 Chambliss is extremely weak with Republicans describing themselves as 'very conservative.' 61% of them would like to replace him, compared to only 23% who would like to see him nominated again. He would trail Cain 68/19 with that group of voters. 
 
 In terms of the general election the Georgia Senate race is somewhat reminiscent of the Indiana contest this cycle- if Chambliss is the nominee the seat is probably safe for the GOP, but if someone far to his right wins the primary the Democrats might have a chance if everything goes their way. ||||| Today is the closest thing to a Super Tuesday this primary season, and the results of voting in six states will set the stage for some of November’s marquee races. 
 
 The Democrats’ best hopes for Senate pick-ups are in Kentucky, where Senate Minority Leader Mitch McConnell faces a tea party-inspired primary challenge, and Georgia, where a crowded field of Republican candidates will be narrowed to a two-way runoff. 
 
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 reset John Harris analysis Primary preview: Kentucky, Georgia Chamber eyes Ky., Ga. Senate races 
 
 Polls finish closing in Kentucky and Georgia at 7 p.m., in Pennsylvania at 8 p.m., in Arkansas at 8:30 p.m. and in Idaho and Oregon at 11 p.m. Here are five themes to watch for as returns come in: 
 
 (Full results: 2014 primary elections) 
 
 In Georgia, will the two most establishment-friendly candidates make it to a runoff? 
 
 David Perdue, a former Dollar General CEO, has led in the final polls of the race to succeed retiring Sen. Saxby Chambliss, and he’s taken the brunt of attacks in recent days. 
 
 His No. 1 antagonist has been Rep. Jack Kingston, who is backed by the U.S. Chamber of Commerce. Both men are battling for a similar base of support as they seek to make the July 22 runoff, and a head-to-head matchup would most likely be very negative. 
 
 Karen Handel, a former Georgia secretary of state, has tried to present herself as the more conservative alternative to Perdue and Kingston. She’s come under fire from two well-known social conservatives in the House, Phil Gingrey and Paul Broun, who have tried to stay in the hunt. 
 
 Democratic star recruit Michelle Nunn faces no real opposition in her primary. 
 
 (Also on POLITICO: GOP war revived in Georgia) 
 
 Because the open Senate seat drew three House members, there are competitive GOP primaries for their seats, each of which could also go to a runoff. Meanwhile, on the Democratic side, Atlanta-area Rep. Hank Johnson is facing a stiff challenge from a former DeKalb county sheriff. 
 
 In Oregon, how damaging is the Monica Wehby police report? 
 
 For months, Republicans have touted Portland neurosurgeon Monica Wehby as a dream recruit to take on freshman Democratic Sen. Jeff Merkley, who they think could be vulnerable because of his support for Obamacare in a state where implementation has been particularly disastrous. 
 
 Wehby faces primary opposition from the more conservative state Rep. Jason Conger but has been backed by national Republican figures such as Mitt Romney and Newt Gingrich. Recent polls showed her well ahead. 
 
 (Also on POLITICO: Second harassment accusation for Wehby) 
 
 Then on Friday, POLITICO reported that Wehby’s ex-boyfriend last year accused her of “stalking” him, entering his home without his permission and “harassing” his employees. Both Wehby and her ex downplayed the incident, saying they are now on good terms. 
 
 On Monday, Wehby received another blow when The Oregonian reported that her ex-husband accused her through their 2007 divorce of “ongoing harassment.” 
 
 Wehby is likely to prevail because Oregon is an all-mail voting state, meaning that many of the ballots were already sent in before the news broke. 
 
 (WATCH: Some of 2014's wackiest campaign ads) 
 
 Oregon Republicans also are choosing a nominee to take on potentially vulnerable Democratic Gov. John Kitzhaber. It’s a pretty deep-blue state, so Kitzhaber should probably be OK come November, despite the major problems with Oregon’s health exchange. 
 
 National Republican Congressional Committee Chairman Greg Walden also is poised to crush a primary challenger in the race for his House seat.
– Saxby Chambliss will announce today that he doesn't intend to run for re-election when his Senate term ends in 2014, sources tell the Atlanta Journal-Constitution. Chambliss reportedly told his senior staff about the decision this morning. Chambliss was considered one of the Republicans most ripe for a primary challenge, the Washington Post observes, thanks to his track record of bipartisan compromise and recent break with Grover Norquist. Potential successors are sure to come out of the woodwork now. Two House members, Paul Broun and Tom Price, had already been considering primary challenges, and more, including Phil Gingrey and Tom Graves, are likely to consider throwing their hats in now. But there are also some bigger name possibilities: A recent poll, for instance, shows that Herman Cain would have trounced Chambliss in a primary, meaning he would be an early favorite if he decided to run.