You're ascribing things to the whole GOP that are just examples of its outlier (and loser) candidates. While they each have followings, both Akin and Santorum are far from the average or median GOP candidate/officeholder. And using Akin's ignorance as an example of anything that "Republicans spew" is especially unfair: not only did his party widely condemn him afterward, but even beforehand I doubt you'd find any prominent GOPers believing that 'rape pregnancy immunity' theory – it was an Akin peculiarity, not a representative belief.

However, the current GOP may be doomed by such fuzzy perceptions and slurs. Most media is overwhelmingly sympathetic to the Dem party, and so even when consciously trying to be fair, they're prone to oversimplifying the GOP based on caricatures and headline-grabbing outliers. Actual strongly-partisan Dem campaigners are happy to assist this process.

Among other things, this is an example of "Out-group homogeneity bias" – http://en.wikipedia.org/wiki/Out-group_homogeneity – the idea that among 'us' there's variety but 'they' tend to be all alike. Highlighting outliers in key negative dimensions (like Akin and Santorum) as if they were representative, central examples of the whole category is part of that biased process.