It's fairly simple, Republicans are not very good at choosing their candidates for national elections, and it has to change.
If you are a Republican and you don't believe this to be true then sooner or later you will not have a party ... and my guess is it will be sooner. The paleo-conservatives, the true Ronald Reagan types, are going to move away and form their own party or reject neo-conservative and religious right platforms. Once the libertarian-leaning Republicans, moderates, and paleo-cons join forces, then it is all over. How can a party which controls the governorships in Michigan, Wisconsin, Pennsylvania, New Jersey, Ohio, Florida, New Mexico, and Virginia lose all of those states or not win at least 4 of them in a Presidential election? If the GOP is going to be relevant on the national stage it has to change and it has to happen now.
John Kasich, Chris Christie, Scott Walker, Tom Corbett, Rick Snyder, Bob McDonnell, and Susana Martinez need to take charge and bring the GOP to its senses.
I used to vote Republican almost religiously until Bob Dole and George W. Bush became presidential candidates, Paul Simon as Senator is the only time I remember crossing the party lines. Now, I often prefer not to vote for a presidential candidate, or a senator or governor in Illinois and write in Mickey Mouse.
Political pragmatism has little utility to most moderates, paleo-cons, and libertarians in the Republican Party while it means everything to neo-cons and religious right who always vote the lessor of two or more evils which in a general election means voting against the Democratic candidate. There is a reason the aforementioned governors in Democratic states are in office, it is their broad reach at disarming democratic turnout differential and bi-partisan nature of their political philosophies which allow them reach and crossover support in urban areas because they are seen as problem solvers with a sense of empathy and responsibility.
Plenty of things went wrong this election for Republicans and it all starts with Romney. Romney read his primary numbers wrong and mixed up his political ideology to ensure he had support of the neo-cons and the religious right after the primary election. Most politicians move towards the center and become robust in platform discussions that are more center based after the primary, but not Mitt Romney. Romney, who is a moderate, ran so hard to right after the primary he ended up looking like a neo-con that when he ran towards the center as the debates neared no one knew what his policies would be including himself. Then he formulated a plan of trying to win Ohio and Wisconsin in all out battle of attrition which stripped of him resources in Virginia, Florida, and North Carolina.
News flash to Republicans, but when you pick a guy from a state that went to the Democratic Party in the last election as your running mate then they know you are targeting that state as a possible swing state. Then all the opponent has to do is the math and bide its time in defensive posture in those states. He knows he only has to spend enough to defend his lead while you waste and draw resources from elsewhere and then attack those areas you drew resources from. If the polls don't tell you this happened then nothing will. You don't lose 3-5 point leads in states unless you withdrew resources to put elsewhere. Republicans talk about decentralization in governing, but are the worst at centralizing power and resources in a national election. If you really want to know why Romney lost this election this was it in a nutshell. Maybe it's better he's not going to be president, because he didn't run a national campaign, and he didn't have reach into urban communities.