Hello, I'm Casey1505, and I approve this question.

I’ve seen this trend on the national level (“I’m Geroge W. Bush, and I approve this message.”), as well as on the local level (“I’m Councilwoman Rottencrotch, and I approve this message.”). It seems that even the fine print has changed from “Paid for by…” to “Approved by…”

Is this a recent change in campaign law? What’s the deal?

I believe it is part of the McCain-Feingold act.

It’s acknowledging that the commercial is part of your campaign and not done by someone just on your behalf.

The McCain-Feingold Act appears to only cover elections on the federal level. Does it, in fact, cover local elections as well, or are those candidates just adopting it to, I don’t know, appear more “politically savvy” than they actually are?

and I quote:

"It is only a few words in the new McCain-Feingold campaign finance law, a rider first attached in the Senate by Oregon Sen. Ron Wyden, a Democrat. The new measure requires “an unobscured, full-screen view of the candidate” making the statement “that the candidate has approved the communication.”