2012 Republican Senate candidate Richard Mourdock (Michael Conroy/Associated Press)

Although the Republicans have made notable gains in the House since 2008, they have not done that well in the Senate.  The problem, the story goes, was the candidates they nominated in some Senate races: Sharon Angle, Todd Akin, Richard Mourdock, and others.  These candidates were simply out of the mainstream, some argued — as evidenced by Angle’s views on immigration, Akin’s comment about “legitimate rape,” and Mourdock’s comment about abortion and rape.  Of course, we don’t know for sure that these things led to their defeat, but there is certainly good circumstantial evidence as well as political science research showing how out-of-step candidates can lose votes.

What’s interesting is how differently things are shaping up in 2014.  In many crucial Senate elections, Republicans have coalesced around politically experienced candidates who make it much more likely that the GOP will win those elections.

Moreover, many of these candidates are likely to be perceived by voters as mainstream conservatives, rather than ideological extremists.  Here’s the evidence.

The political scientist Keith Poole took a large national survey from October 2012 that asked people to place various political figures on a liberal-conservative scale, including House or Senate candidates in their district or state.  Fortunately, many of this year’s Senate candidates were running for office in 2012.  Here is Poole’s graph of where voters placed these candidates as well as Obama, Romney, the Supreme Court, and the tea party:

Compare the locations of Mourdock, Akin, and the tea party to those of the current GOP candidates — Brown, Cassidy, Daines, Capito, Cotton, and Gardner.  These candidates were perceived to be less conservative, substantially less so in Scott Brown’s case.  For all except Brown, voters placed them essentially where they placed Romney.

Moreover, some of the Democratic candidates running in Republican-leaning states, particularly Landrieu, may be challenged by their perceived proximity to Barack Obama.  As Poole notes:

All of the Democrats are perceived to be closer to the center than President Obama, with Sen. Jeanne Shaheen (D-NH) as the most liberal of the group and Sen. Mark Pryor (D-AR) as the most moderate. Interestingly, Sen. Mary Landrieu (D-LA) is perceived to be slightly more liberal than Sen. Kay Hagan (D-NC) and considerably more liberal than Pryor by Louisiana voters. This does not bode well for her in her race for a fourth term.

Granted, these data are from 2012, but I doubt that voters’ perceptions have changed much since then.  The bigger question is whether they will change between now and November.  If not, then unlike in 2010 or 2012, the GOP may not give away Senate elections that it otherwise had a good chance of winning.