Enough with the political abstractions like Intrade and Democratic political consultants fighting in the lifeboats. The 538 article you flagged (could've been boiled down to one sentence: 'All politics is local.' (But now apparently, we have the data to support that.) To these eyes, the money paragraphs in the 538 piece on Brown are:
"In 2002, he filled out a Votesmart survey on his policy positions in the context of running for the State Senate. Looking through the answers doesn’t reveal too much beyond that he is a pro-choice, anti-tax, pro-gun Republican. His interest group ratings are all over the map. Business and gun rights groups typically rate him very highly, labor and and environmental groups have rated him both middling and high over time. The teacher’s union rated him low in 2001, and high in 2005.
All in all, a very confusing assessment, and quite imprecise..."
My goodness! He might be a 21st century moderate, with the occasional ideological inconsistencies that implies. Or at least, a moderate for Massachusetts, if all politics are local.
It's not that complicated: no matter who wins Tuesday, we are seeing the emergence of a non-ideological Reality-Based-Community 2.0. The 1.0 RBC flagged up questionable philosophy and disastrous execution in the War on Terror (especially) and Washington corruption... hey, wait a minute, so does the 2.0 version of RBC! But with quite different views, and hardly doctinaire conservative views - you don't need to be a Dittohead to be alarmed about this and this, not to mention this and this (http://www.scrippsnews.com/content/murdock-obamacare-can-cost-you-your-health-insurance), and most of all, this.
Look at what's happening with Independents here (and one suspects nationally). Many members of RBC 2.0 found common cause with RBC 1.0 views, but not with the policy counter-prescriptions and (most importantly), not with the results of those prescriptions. And there are some differences: RBC 1.0 idea of a longterm problem is climate change. RBC 2.0 idea of a longterm problem is college tuition. These are not diamatetrically opposed to each other, but the scope and priorities for decisionmaking are quite different.
From that local perspective (again), Jon Keller just summarized the RBC 2.0 backdrop quite nicely. Go out, drive around his weekend and count the lawnsigns...