Dems can hold Senate

The early 2012 conventional wisdom was that Republicans would easily take control of the Senate this November. It was a perfectly reasonable supposition — 23 Democratic seats are up for reelection, with the GOP defending just 10. Given that Republicans need a net pickup of only four seats for an outright majority, the numbers appeared to be squarely in their favor.  

But elections have a funny way of confounding even the surest predictions, and it’s increasingly evident that Mitch McConnellMitch McConnellSchumer blocks one-week stopgap funding bill Overnight Finance: Dems explore lawsuit against Trump | Full-court press for Trump tax plan | Clock ticks down to spending deadline Hundreds of former EPA employees blast Trump on climate change MORE might want to hold off on ordering those new business cards.

Six of the seats where Democrats are playing defense are in red states, and one of them is Missouri Sen. Claire McCaskillClaire McCaskillFive takeaways from the Georgia special election Picking 2018 candidates pits McConnell vs. GOP groups Potential McCaskill challenger has .7M: report MORE’s. McCaskill remains the most endangered Democratic incumbent, her hopes resting on a nasty GOP primary that might produce a weakened opponent. And in Nebraska, Democratic former Senator and Gov. Bob Kerrey trails badly, although he’s making Republicans spend money in a state they had chalked up in the win column just a few months ago.

But in North Dakota, where Republicans thought they had an easy pickup when Sen. Kent Conrad retired, former Attorney General Heidi HeitkampHeidi HeitkampDems struggle with abortion litmus test Lawmakers reintroduce online sales tax bills Overnight Regulation: Senators call for 'cost-effective' regs | FCC chief unveils plans to roll back net neutrality MORE leads in the early polling. And West Virginia’s Joe ManchinJoe ManchinDems struggle with abortion litmus test Senators push 'cost-effective' reg reform Congress nears deal on help for miners MORE is headed toward an easy reelection after narrowly winning the seat in a 2010 special election. 

The final two Democratic seats in red states, Montana and Virginia, are both neck and neck — same as they were in 2006, when their outcome decided control of the Senate. We could see a repeat this November. 

Republicans have targeted open Democratic seats in New Mexico and Wisconsin, both fiercely competitive. However, Wisconsin will be far less competitive if Republican primary voters reject their best candidate, moderate former Gov. Tommy Thompson. 

Beyond that, Republican challenges to Democratic incumbents in Florida, Michigan, Ohio and Pennsylvania all appear to be fizzling. Florida Republicans have failed to recruit a top-tier challenger to Sen. Bill NelsonBill NelsonLawmakers stare down challenge of cyber-enabled ‘fake news’ United explains passenger removal to senators Overnight Cybersecurity: Ex-officials warn 'Buy American' might harm Pentagon cybersecurity | Chair nudges Trump on cyber order | House gets security training MORE, who has commanding leads in polling. Ditto with Pennsylvania. In Michigan, former GOP Rep. Pete Hoekstra cratered after airing a racist attack ad during the Super Bowl, and never recovered in his bid to unseat Sen. Debbie StabenowDebbie StabenowMedicare’s coverage decisions need more input from physicians Members help package meals at Kraft Heinz charity event in DC Senate braces for fallout over Supreme Court fight MORE. And in Ohio, no non-presidential candidate has faced more negative super-PAC money than Sen. Sherrod BrownSherrod BrownTrump talks big on trade, but workers need action Dems crowd primaries to challenge GOP reps Battle begins over Wall Street rules MORE, yet he has weathered at least $5 million in attacks with limited erosion in support. 

As of today, that means the GOP is favored in two states and faces toss-up battles in perhaps five more. Remember, they only need four of those to win control, but that’s assuming they don’t lose any seats.

And make no mistake — the Democrats are also playing offense. 

There’s a real fight in Massachusetts, where Republican fluke Sen. Scott Brown is facing grassroots superstar Elizabeth WarrenElizabeth WarrenSanders: Obama's 0K Wall Street speech 'unfortunate' Trump retweets Fox News video on Warren criticizing Obama Senate confirms Labor Secretary Acosta MORE. In Maine, left-leaning independent and former Gov. Angus KingAngus KingSenator: No signs of GOP 'slow-walking' Russia investigation Republican Sen. Collins considering run for Maine governor in 2018 Conway: Dems should listen to their constituents on tax reform MORE is likely to capitalize on Republican Sen. Olympia Snowe’s retirement.

Democrats are also competitive in Nevada and Arizona, where changing demographics are transforming the political landscape. 

And then there’s Indiana, which really should be safely Republican. Yet conservatives gifted Democrats with an opening by ousting longtime incumbent Dick Lugar in the GOP primary. Democratic nominee Joe DonnellyJoe DonnellyDems struggle with abortion litmus test What prospective college students need to know before they go — or owe Battle begins over Wall Street rules MORE, a sacrificial lamb against Lugar, is even money against conservative darling Richard Mourdock. 

With Democrats in good position to take two Republican seats, and competitive in three more, it’s clear that the GOP’s path to the Senate majority is a whole lot more treacherous than it seemed a few short months ago.

Moulitsas is the publisher and founder of Daily Kos (