I think this might have an appreciable effect on the KKT-Ehrlich race. I hadn't really thought about it before-- only thinking about how this might affect feelings on gun control.
I'm a little queasy about speculating on the effects of the sniper on politics, but... the impact could be national, in a subtle way, in that it may tend to crowd politics off of the first page of the papers, and out of the lead on the TV news and talking head shows. Which way this will cut, I have no clue. Probably it works in favor of whichever candidate is leading in a given race. Come-from-behind hopes based on anticipated late advertising blitzes may be frustrated, if nobody's paying attention.
I fully understand the sentiments of those who think political analysis as it relates to this horror is inappropriate, but elections go on regardless. As far as the Maryland race is concerned, I'd think both candidates would be walking on eggshells. Any perception that either of them are attempting to politicize this situation is likely to be dealt with harshly by the electorate.