The McCain camp was wary, while the Democratic primary still looked undecided, of taking on Barack Obama too forcefully. Yes on Hamas and Bill Ayers, no on Reverend Wright, with not much fire directed at some of the recent Obama gaffes. Now that the primary is drawing to an end, the McCain camp may be stepping up its rhetoric, and the rules of engagement are being set.

After the John Edwards endorsement event in Michigan last night, the McCain camp put out a statement which took Obama to task in some of its strongest language to date:

Whether it’s Senator Obama’s pledges to raise taxes on millions of hardworking families or his senseless foreign policy of meeting with anti-American regimes abroad, he shows a lack of judgment that voters will reject.

Staffers also sent out some stats from their research files detailing the lack of bipartisanship in Obama’s record, in advance of McCain’s speech today on bipartisanship.

Likewise, when Obama’s communications director Robert Gibbs tried to hedge on Obama’s position that he will meet directly with state sponsors of terrorism (“Let’s not confuse precondition with preparation,” he told John Roberts during a CNN interview), the McCain team struck back. With plenty of YouTube material and Obama’s own website detailing the candidate’s repeated determination to meet with rogue states’ leaders without preconditions, it wasn’t hard to show that Obama’s spokesman had been engaging in old-style double talk.

McCain’s people will need to do more of this if they are going to force Obama to define what “change” is and make clear exactly what policies he has in store. Allowing Obama to escape scrutiny in a media environment already shown to be excessively deferential to the Agent of Change would be a grave and even fatal error: It’s one Hillary Clinton made for all of 2007.