If members of the Santorum team would take a step back and look at the scene, Newt’s team did that weeks ago, by running no ads and making no visits (except for the debate) in either of those states.
Newt’s too busy other places. He’ll make the ten percent he needs without campaigning. Both of those states are a wash. MI because it’s proportional and not worth the effort for so few delegates, and AZ because of the large Mormon population that only Romney money can buy.
That is nonsensical, because the vote for Gingrich would accomplish the same thing, but that's the perception. In fact, the only reason Santorum was able to rise from obscurity by "winning" nonbinding delegates in Minnesota and Missouri, is because he was a beneficiary of neither Gingrich nor Romney campaigning there. Outside of Midwest / labor union states, Santorum has hardly any appeal.
The plan is to rack up delegates in large proportional states and win large all-or-nothing states. To that extent, Santorum's "mini-surge" can be a detriment, but in some states it could also be of benefit since a large part of Santorum voters are much closer to big-government Romney than to small-government/Tea-Party Gingrich, so as long as that part keeps voting for Santorum, it's fine - they don't give delegates to Romney.
It's important to notice that while many polls show both Romney and Santorum fighting for the "win," they are still only getting around 30% of votes and, with Paul at usually stable 10% or single digits, this should leave about 30% to Gingrich... but there remains a large percentage of "undecided" who may be swayed by the polls and the notion that Santorum needs their "strategic vote" to "win" in the state to "deny" delegates to Romney.
Since "winning" the state like MI or AZ is irrelevant (except for bragging rights) and this is the wrong kind of "strategic vote" thinking - "natural" Gingrich voters (at least on FR) should be educated about this.