Republicans began the 2012 election cycle expecting to win the four seats needed for Senate control. Instead, they ended up down two seats, largely because of poor recruitment and candidate gaffes.

For Democrats, they held off a GOP take-over attempt of the upper chamber for the second cycle in a row. This year, they won all but one of the most-tightly contested Senate races, including in three states most expected them to lose: Indiana, Missouri and North Dakota. They had twice as many seats to defend this cycle, and a number were in red states.

{mosads}Republicans, meanwhile, won only one new seat, in ruby red Nebraska, and lost three others in Massachusetts, Maine and Indiana. They did retain seats in Nevada and Arizona, where Democrats had surged but failed to defeat Sen. Dean Heller (R-Nev.) and incoming-Sen. Jeff Flake (R-Ariz.)

National Republican Senatorial Committee Chairman John Cornyn (R-Texas), who for the second time failed to capture a majority for his party, was the first to admit the GOP’s problems.

“It’s clear that with our losses in the presidential race, and a number of key Senate races, we have a period of reflection and recalibration ahead for the Republican Party,” Cornyn said in a statement on Tuesday night. “While some will want to blame one wing of the party over the other, the reality is candidates from all corners of our GOP lost tonight. Clearly we have work to do in the weeks and months ahead.”

Cornyn predicted back in August 2010 that Republicans would win control of the Senate by 2012. Instead they fell five seats short.

No single event or trend led to the Democrats’ huge night.

But their chances were boosted by gaffes from Republican nominees in Missouri and Indiana. Rep. Todd Akin (R-Mo.) became the subject of national attention when he made his controversial comments on “legitimate rape.” Republicans tried to get him withdraw from the contest but he prevailed, despite the NRSC lack of public support. In Indiana, Republican Richard Mourdock came under fire for his controversial explanation of why he didn’t believe in abortion in cases of rape: “Even when life begins in that horrible situation of rape that it is something God intended to happen,” he said.

The failure of Akin and Mourdock led to comparisons of the 2010 busts from GOP candidates Sharron Angle in Nevada, Christine O’Donnell in Delaware and Ken Buck in Colorado, whose primary wins likely cost the GOP seats they expected to pick up. Akin won a competitive GOP Senate primary and Mourdock defeated longtime Sen. Dick Lugar in their primary — two wins which boosted Democratic hopes of winning in those states. If all five of those races had gone to the Republicans they would be at 50-50 parity in the Senate.

Cornyn and the GOP also failed to recruit strong candidates in a number of competitive swing states, most notably in Florida and Ohio, where Rep. Connie Mack’s (R-Fla.) campaign got caught up in a public battle with a prominent Florida political reporter and Republican Josh Mandel never caught fire against Sen. Sherrod Brown (D-Ohio).

The GOP also didn’t offer serious challenges in the slightly Democratic-leaning states of Michigan and Minnesota.

Mitt Romney’s decision not to seriously contest Michigan and Pennsylvania also made it more difficult for Republicans to win there.

And Democrats proved to have better candidates in open seats in North Dakota, Virginia and Wisconsin. Democrat Heidi Heitkamp ran a smart, tough campaign in North Dakota and she won a close race there. Democrats Tim Kaine in Virginia and Rep. Tammy Baldwin in Wisconsin also prevailed in races considered toss-ups.

Meanwhile, several strong Republican candidates where hurt by their party’s poor image in their states. One of the toughest losses for the GOP was in Massachusetts, where freshman Sen. Scott Brown (R-Mass.) ran away from his party but still lost to Democrat Elizabeth Warren. Republicans Linda McMahon in Connecticut, Heather Wilson in New Mexico and Linda Lingle in Hawaii also touted their independence but ultimately lost. President Obama’s win in those states was some help, offering Democrats slight coattails.

Ultimately, the 2012 setbacks complicate GOP chances of winning control of the Senate in 2014. Democrats will once again be playing defense in many more states, having to defend seats in six red states: Alaska, Arkansas, Louisiana, Montana, South Dakota and West Virginia.

They also have seats up in the swing states of Iowa, Michigan, Minnesota, New Mexico, North Carolina and Virginia, while Republicans’ only possible tough seat is in Maine, but if Sen. Susan Collins (R-Maine) runs for reelection she’s likely in good shape.

Republicans now need to net six seats to put Senate Minority Leader Mitch McConnell into the majority leader’s office  — a much more difficult task.