That's one way to look at it
Matt notes that "Stith has strong ties to the Republican Party but has not emphasized his political affiliation, for obvious reasons. He thinks his Republican status should be irrelevant in a non-partisan race."
There's two ways to read that, i think. One is that there are reasons why Stith has remained silent about his party affiliation, and discerning readers know what they are. The other is that "the obvious reason" why Stith has not played up his Republican credentials is that he thinks it "should be irrelevant in a non-partisan race." I think the latter is what Matt is saying.
But i think the former is the case. Stith's initial foray in the race played on one of the favorite hot-button issues of Republicans nationwide - illegal immigrants. That didn't pan out so well for the candidate, and he quickly switched gears to a series of personal attacks against incumbent mayor Bill Bell. But Stith's conservative agenda, his Republican credentials (he sought the Republican nomination for Lt. Governor in 2004), his ties to Art Pope's reactionary Civitas Institute are all issues in the campaign, whether Mr. Stith wants them to be or not. His tactics in this campaign, borrowed heavily from Republican strategists, are issues in the campaign. It's a bit disingenuous of him to try to claim the high road at this point in time.