Today in the Morning Line:

Two names that could stop the Republican Senate takeover: Pryor and Begich

Three more arrested in Mississippi in Cochran case

Democratic candidates turn on Shinseki

Castro’s turn in the national spotlight

The GOP’s narrow path to a majority: We wrote this week about how the pieces are falling into place for Republicans to take back the Senate with how things have shaken out in North Carolina, Kentucky, Georgia and Oregon. But Thursday, the New York Times Upshot Senate control model, based on public polling, showed Democrats with a 57 percent chance of actually retaining control of the Senate. How can this be? Well, it’s largely because polls over the last month and a half have consistently shown Democrat Mark Pryor ahead in Arkansas and even Republicans say Democrat Mark Begich in Alaska is running a very good campaign. How key are Arkansas and Alaska? Consider: With Republicans needing to net six seats to win control and Democrats currently either slightly ahead or better in all of the competitive races in Obama-won states — Colorado, Michigan, Iowa, New Hampshire and Oregon — that leaves Republicans with a very narrow window. If the GOP holds Kentucky and Georgia, which became more likely after this week’s primaries, and it wins South Dakota, Montana and West Virginia as expected, then Republicans need three more pick-ups. That means they need to win three of four of the remaining red-state races with Democratic incumbents — Louisiana, North Carolina, Arkansas and Alaska. For argument’s sake, if you give Republicans North Carolina and Louisiana, but they lose Arkansas and Alaska, they come up one short.

The case for a sense of urgency: Republicans need to capitalize on 2014, because the 2016 map is far less favorable to them. First, it’s a presidential year with a far more pro-Democratic electorate than in midterms, and second, several Republican incumbents will be up for re-election on more Democratic-leaning turf, unlike this year. Among the seats the GOP will have to defend: Florida (Marco Rubio), Illinois (Mark Kirk), Iowa (Chuck Grassley), New Hampshire (Kelly Ayotte), North Carolina (Richard Burr), Ohio (Rob Portman), Pennsylvania (Pat Toomey) and Wisconsin (Ron Johnson). President Barack Obama won seven of those eight states in both of his campaigns — and earned a split in North Carolina, taking the state in 2008 and losing it to Mitt Romney by just two points in 2012. The only competitive seats Democrats will have to defend are in places Obama won and where Latinos factor prominently — Nevada (Harry Reid) and Colorado (Michael Bennet). That puts pressure on Republicans to not only win control this cycle, but to do so with a cushion to retain it two years from now. What would a 51-to-49 split likely get Republicans? Control of the Senate for the last two years of a Democratic presidency, and Obama would block any attempts to dismantle the Affordable Care Act or other Republican-backed measures he finds objectionable. So, it’s possible we could be looking at a lame-duck president AND a lame-duck Senate from the start of the next Congress — unless everyone can work together. Don’t everyone inhale and hold your breath all at once…

Mississippi mess — McDaniel supporters arrested in Cochran case: Republicans’ path would become much more complicated if tea party-backed state Sen. Chris McDaniel pulls off the once-thought-to-be improbable upset over incumbent Thad Cochran June 3. That, however, is looking less likely with the arrests Wednesday of three McDaniel supporters, including a Mississippi tea party leader in connection with the alleged illegal photographing of Cochran’s wife, who suffers from dementia and is bed-ridden in a nursing home. That makes four people now arrested in the case. One of the men occasionally co-hosted a radio show with McDaniel. The McDaniel campaign denies any involvement: “As we have said since day one, the violation of the privacy of Mrs. Cochran is out of bounds for politics and is reprehensible. Any individuals who were involved in this crime should be prosecuted to the fullest extent of the law.”

Democratic candidates call for Shinseki to resign: How much of a political football has the VA scandal become? A day after President Obama did NOT call on embattled Secretary Eric Shinseki to step down, some Democratic candidates in competitive races did exactly that: Alison Lundergan Grimes, running against Republican Senate Leader Mitch McConnell in Kentucky, Charlie Crist, running for governor of Florida against incumbent Republican Rick Scott, House candidate Aimee Belgard, running in the swing New Jersey 3rd Congressional District, and Rep. Steve King’s challenger in Iowa. That’s in addition to Georgia Reps. John Barrow and David Scott, who previously did so. “We owe a solemn obligation to our veterans,” Grimes said, “and our government defaulted on that contract. I don’t see how that breach of trust with our veterans can be repaired if the current leadership stays in place.” That was further than McConnell, who hadn’t explicitly called on Shinseki to resign, had gone to that point. After Grimes released her statement, though, McConnell said he was glad Grimes was following his lead. This has become a way for some Republicans who don’t want to talk about Benghazi to find a way to criticize the administration, and for Democrats who need some separation from Obama to do so. And that’s not a good position for the White House or Democrats.

Castro comes to Washington: San Antonio Mayor Julian Castro will officially be named as President Obama’s pick to be the next Housing and Urban Development secretary at a 3:35 p.m. ET event at the White House Friday, a White House official confirms for Morning Line. He would replace Shaun Donovan, who is moving from HUD to be the president’s budget director. Castro is considered a Democratic rising star, but whether the move is good for him politically is unclear. It was thought that if Castro could win statewide in Texas, it would vault him to national prominence. But despite the state’s changing demographics, it’s still not exactly friendly terrain for Democrats. Coming to Washington could give Castro, who is Mexican-American, more of a national platform, but some Latinos are split on the move. Ruben Navarrette writes in the Dallas Morning News, “Serving in the Cabinet means defending the president who put you there, and Barack Obama’s relationship with Latinos is sketchy due to a record number of deportations of illegal immigrants. … As Castro deepens his association with Obama, where will that leave his Latino supporters? Answer: With what I have now: mixed feelings.”

Daily Presidential Trivia: On this day in 1955, then-Senator John F. Kennedy returned to the Senate after back surgery and a 7 month recuperation period. Along with chronic back problems, what other serious medical condition did Kennedy suffer from? Be the first to Tweet us the correct answer using #PoliticsTrivia, and you’ll get a Morning Line shout-out. Congratulations to Carmen Pi Caride ‏(@sweetbrazilian1) for correctly guessing Thursday’s trivia: When Nixon became the first president to visit Russia, with whom did he meet? The answer was: Leonid Brezhnev.

A note to our readers: We will be taking the Memorial Day holiday off from Morning Line. We will be back Tuesday. Have a great holiday weekend!

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TOP TWEETS

Press corp reax: https://t.co/8DrJmBnm7y RT @RalstonReports: BREAKING: Las Vegas withdrew from the RNC's site selection for 2016 convention — Nick Confessore (@nickconfessore) May 22, 2014

History: President Obama looks at a Jackie Robinson jersey as he tours the National Baseball Hall of Fame pic.twitter.com/KgAJASgcmL — TheObamaDiary.com (@TheObamaDiary) May 22, 2014

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