The year of the upset this is not. So far, at least.

Democratic Rep. Ed Markey's Senate special election victory in Massachusetts on Tuesday was widely expected. It was the political equivalent of Occam's Razor -- the simplest explanation tends to be the right one. The same can be said of the rest of the 2013 special election landscape thus far.

If you're looking for clues about how the national political environment might be influencing this year's elections, you'll be disappointed. The races have not been referenda on broad themes; rather, they have been reflections of the natural political tilts of their specific states and districts.

Democratic Senator-elect Ed Markey with his wife, Susan Blumenthal, was expected to win in Massachusetts. (Elise Amendola/Associated Press)

Running in deep blue Massachusetts with substantial Democratic reinforcements from the get-go, Markey was poised for victory -- barring an upset in the political environment that could have prompted Massachusetts voters to betray their reliably Democratic leanings or a major misstep by the candidate.

The same can be said of now-Rep. Mark Sanford (R-S.C.), the former governor whose win in a reliably conservative district in May was a product of, well, voters in a reliably conservative district going with the more conservative and better-known candidate. (And implicitly forgiving his past indiscretions.)

Rep. Jason Smith (R-Mo.) won a special House election in a heavily conservative Missouri district as expected. And Rep. Robin Kelly (D-Ill.) earlier won in a very blue district.

In other words, dusting for fingerprints in these races would reveal much more about Massachusetts, the South Carolina Lowcountry, southeastern Missouri and the Chicago suburbs than it would about Washington and the rest of the country.

It's not surprising. The campaigns took place in heavily Democratic or heavily Republican states and districts -- not swing or even swing-ish areas. For there to be an upset based solely on national politics, things would have to be really bad or really good for one party or the other.

They were neither. But that could still change because it's still very early.

Signs that things were going to be bad for Democrats in 2010 emerged in late 2009 -- when Republicans won the New Jersey and Virginia gubernatorial races -- and in early 2010, with Scott Brown's win in Massachusetts. We aren't at those comparable points in the cycle.

We also have yet to see real macro-message testing on issues in any of these races. In 2011, there was message testing over Medicare in New York's 26th district (where Republicans handled it badly) and Nevada's 2nd District (where they handled it better). And in Wisconsin state Senate recall races that year, broad arguments were test driven by both parties.

Sure, a Democratic primary disagreement over gun laws propelled Kelly to victory in her race this year. But that was in a  populous urban/suburban area, and voters there view gun control differently than other voters across the country -- one need only look to the failed push to pass expanded background checks in the Senate.

So, now there are few, if any, clues about the larger political arena from what we have seen in these special (or perhaps not-so-special, if you were looking for clues) elections.