Senate Republicans set out Wednesday to pin the blame for their stunning two-seat net loss in Tuesday’s elections. But instead of soul searching about why they failed again to capture the Senate majority, they tipped their hat to Democrats’ ability to outflank them.

Flawed GOP nominees in the eminently winnable races in Indiana and Missouri were the easiest scapegoats, but a whole crop of solid, mainstream recruits fell in swing states and other friendly Republican territory.

Though Republicans pointed to political headwinds for their losses in some initially promising races and bad luck in other areas, they said the results were mainly due to better execution by the Democrats.

“There’s definitely some frustration about Indiana and Missouri,” Republican pollster Dan Judy said. “I think there’s going to be a temptation on the part of some folks — and a concerted effort by Democrats — to say, ‘Well, the GOP just nominated a bunch of tea party crazies again, which is why they got wiped out.’ But I don’t think the map bears that out.”

After the last two Senate races were called midday Wednesday, Republicans ended the cycle with a net loss of two seats — a nearly inconceivable notion just a year ago, when Congressional observers gave the GOP good odds to win the majority. It turned into as bad a night as possible for the National Republican Senatorial Committee.

As the 2012 cycle progressed,races that once appeared ripe for the picking fell off the table for Republicans, one by one, ultimately leaving Democrats with an expanded majority of 55 seats. Republicans entered the cycle needing to net four seats to flip the chamber. They were aided by the makeup of the cycle, as the party was defending just 10 out of the 33 seats up this year.

But distasteful comments about rape by Rep. Todd Akin (R-Mo.) and Indiana Treasurer Richard Mourdock (R) essentially handed two victories to the Democrats in contests they were otherwise likely to lose, in states where Republican presidential nominee Mitt Romney cruised to victory. Republicans picked up just one Democratic-held seat and lost three of their own and not a single Democratic incumbent was defeated.

The Democratic Senatorial Campaign Committee, led by Chairwoman Patty Murray (Wash.) and Executive Director Guy Cecil, recruited strong candidates who ran near flawless campaigns and were successful in states few thought possible earlier in the cycle.

“The reason we were competing in North Dakota and Arizona is because of the candidates,” Democratic pollster Jef Pollock said. “Kudos to the DSCC, to Sen. Murray, to Guy Cecil, to the folks at the DSCC, for putting major league candidates in place that made many of these races competitive.”

A star recruit of Murray’s, former Surgeon General Richard Carmona (D), came up short in Arizona against Rep. Jeff Flake (R). But former North Dakota Attorney General Heidi Heitkamp (D), whose victory was the last to be called on Wednesday, defeated Rep. Rick Berg (R), and Sen. Jon Tester (D-Mont.) defeated Rep. Denny Rehberg (R). Both victories came in states Romney carried by double-digits and against statewide elected officials.

“I still believe it’s all about the type of campaign a candidate runs,” Republican media strategist Erik Potholm said. “Heidi Heitkamp turned out to be a great candidate, ran an impressive campaign and she won in a tough state for Democrats.”

It remains unclear whether the NRSC and Chairman John Cornyn (Texas) shoulder all of the blame for Tuesday’s outcome in the coming days — Cornyn is running for the open Senate Minority Whip position. On Wednesday, several GOP Hill sources said the drubbing had led to speculation that Cornyn or other leaders could face a challenge.

But Mike Slanker, the top political adviser to Sen. Dean Heller (Nev.), one of the few success stories for Senate Republicans on Tuesday, lauded the NRSC and Executive Director Rob Jesmer for their efforts in what turned out to be a tough cycle for Republicans.

“My perspective on the NRSC this cycle is they did a hell of a job. They raised a bunch of money, they got it out the door, they helped us tremendously, they were an efficient operation,” said Slanker, who served as NRSC political director in 2008.  “Some things are just out of your control, and they had a lot of that this cycle.

“Looking back, you take away two candidates who shot themselves in the foot, we win those two states,” Slanker added. “And Mitt Romney performs within a point or so in all these swing states and everything changes. It’s a different night.”

There is no doubt that President Barack Obama’s surprisingly strong re-election had some effect on the composition of the Senate, even though statewide races are often able to buck the national trend.

Democrats won the Senate races in the competitive presidential states of Virginia, Ohio, Wisconsin and Florida, where the Obama campaign’s turnout efforts were unmatched and Romney ran worse than expected.

Democrats also were able to put in play five Republican-held seats in Nevada, Arizona, Massachusetts, Indiana and Maine, winning Massachusetts and Indiana and hoping that Maine’s Independent Senator-elect will caucus with the party. Few expected that in the weeks following the 2010 elections, when Murray was the only Democrat willing to chair the DSCC.

“When I took over the chair at the DSCC, we had a very large map, a lot of challenges that were handed to us,” Murray told reporters Wednesday. “And I told everyone I was going to fight to make sure we had a chance in every single state.”

The map again looks difficult for Democrats going forward, and they’ll be running in Obama’s second midterm election cycle, which has historically made things more difficult for the incumbent party. Even as Republicans were recovering from a rough Tuesday night, some found solace in the fact that 2014 is just around the corner.

“The silver lining for the GOP is that the Democrats have a lot of seats to defend in 2014, so we’ll have an opportunity to make some gains, and hopefully extend them in 2016 with an open presidential race,” Judy said. “But there’s no question that we need to improve on what we’ve done over the last two cycles.”

David M. Drucker contributed to this report.