View of the U.S. Capitol dome in Washington, DC on April 23, 2013. (Linda Davidson/The Washington Post)

In a party where good news has been hard to find over the past two years, the current state of play in 2014 Senate races gives Republicans some reason to smile.

A combination of raw numbers, a shift in the political environment and some notable recruiting failures has handed Senate Republicans a realistic — but by no means certain— chance of picking up the six seats they need to win back control of the chamber.

This was always going to be a good election cycle — numbers-wise — for Senate Republicans. They are defending just 14 seats, compared with 21 for Democrats. And of those 14 seats, just one — that of Maine’s Susan Collins — is in a state that President Obama won in 2012. By contrast, one-third of the Democrats up for reelection in 2014 represent states former Massachusetts governor Mitt Romney carried in 2012.

(Of course, the 2012 Senate playing field was also, by the numbers, tilted heavily to Republicans, and Democrats wound up picking uptwo seats thanks to surprising wins in GOP-leaning territory such as Indiana, Missouri, Montana and North Dakota.)

The way the races have played out to date — with the caveat that it’s May 2013, not September 2014 — also has worked broadly in Republicans’ favor.

Six Democratic incumbents are retiring, and only two are doing so from safe Democratic states. Retirements in South Dakota, Iowa, Montana and West Virginia all pose risks for Democrats. Michigan is a state that Republicans will make noise about but ultimately aren’t likely to win. Ditto New Jersey, where Sen. Frank Lautenberg is bowing out but Newark Mayor Cory Booker (D) seems set to replace him.

Just two Republicans are retiring — Sen. Saxby Chambliss of Georgia and Sen. Mike Johanns of Nebraska. Both are vacating states that went for Romney and seem likely to elect Republicans, barring the unexpected.

Recruitment — or a lack thereof — also has handed Republicans a bit of momentum.

In South Dakota, former representative Stephanie Herseth Sandlin and U.S. Attorney Brendan Johnson, the son of the retiring Sen. Tim Johnson, have both passed up the chance to run for the Democratic nomination. While Republicans may face a primary between former governor Mike Rounds and freshman Rep. Kristi Noem, the winner will be considered a clear favorite over likely Democratic nominee Rick Weiland.

It’s the same in West Virginia, where a series of big-name Democrats have said no, leaving the party without a clear next step in terms of a candidate. Meanwhile, Rep. Shelley Moore Capito looks like the clear favorite to be the Republican nominee, although she will have to face a primary opponent from her ideological right.

Republicans have had their fair share of recruitment problems, too, most notably in Iowa, where the party has watched a cavalcade of candidates bow out as Democrats landed their first choice in Rep. Bruce Braley. In Nebraska, Gov. Dave Heineman’s decision not to run means a more wide-open Republican primary, but the state’s strong GOP tilt probably keeps the race from being all that competitive.

The national political environment in which these races are being run has, according to nonpartisan analyst Stu Rothenberg, moved in Republicans’ direction of late as well — thanks to a series of scandals and investigations that have foisted negative attention on the Obama White House. “The change in focus creates much more danger for Democrats that 2014 will be a referendum on the Obama administration, and increases the chances of stronger Republican turnout,” Rothenberg writes in his May 21 newsletter.

Because of that shift nationally, Rothenberg moved five Democratic seats — in Montana, Louisiana, Arkansas, Alaska and North Carolina — into more-vulnerable territory. Charlie Cook, another independent political handicapper, rates 11 Democratic-held seats as “lean Democratic” or worse for the party; there is not a single Republican seat rated as that vulnerable by Cook.

Assuming Republicans lose none of their own seats — the only possibilities are the one held by Sen. Mitch McConnell (R-Ky.) and the open seat in Georgia — and win the two Democratic seats where they are clear favorites right now (South Dakota and West Virginia), that would leave them needing four more pickups to win the majority.

To get there, they would need to win two-thirds of the remaining Democratic seats in jeopardy: open seats in Iowa and Montana as well as those held by endangered incumbents in Alaska, Arkansas, Louisiana and North Carolina.

Neither of the open seats looks like a great chance right now — there’s no GOP candidate in Iowa, and it’s likely that popular former governor Brian Schweitzer (D) runs in Montana — which would mean that to get the majority, Republicans would need to beat all four targeted incumbents. Possible, but not probable.

Still, developments over the first few months of the year have worked in Republicans’ favor. They need a few more good months — with a surprise retirement by a Democratic incumbent, or an unexpected recruitment success or failure — to build on their momentum and make their chances of a Senate takeover a true tossup.

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