Wisconsin Gov. Scott Walker (R) may not have decided whether he's running for president in 2016 but he's already acting like a candidate.

Witness this tweet he sent this morning:

The quick back story: New Jersey Gov. Chris Christie (R), himself a likely 2016 candidate, has caught considerable heat for being a Dallas Cowboys fan. That criticism peaked over the weekend when, after Dallas beat the Detroit Lions in a playoff game, Christie was captured on TV awkwardly hugging Cowboys owner Jerry Jones. (Jones has subsequently said Christie is "part of our mojo.") The Cowboys win means the team will travel to Lambeau Field this weekend to take on Walker's home-state Green Bay Packers. Hence the tweet.

You can be sure Walker will write it off as just a bit of fun. But it's not.  Like most humor, there's a cutting edge right beneath the surface.  Walker is presenting himself as an average guy (the Packers are publicly owned a publicly owned, non profit) while casting Christie as someone who not only pals around with millionaires, but millionaires like the much-loathed Jones.

Make no mistake that Walker knows what he is up to here. He's poking a potential rival -- even as he considers running for president. And it's not the first time he and Christie have clashed. At the end of the 2014 campaign, Walker dismissed the impact of a visit to his state by Christie who was, at the time, the chairman of the Republican Governors Association. Christie "is coming because he asked if he could come and we weren’t going to say no,” Walker said. “But we’re not looking for surrogates. The people that have been campaigning with me are by and large from Wisconsin.” Oomph.

For what it's worth, here's what Walker told conservative talk radio host Hugh Hewitt on Tuesday about the possibility of a presidential bid:

"I think with what I’ve had to go through in the last four years, both politically, but also in terms of the policies, certainly I feel that there’s a reason God put me in a spot to do the things that we’ve done and take on the kind of challenges we’ve done. And it’s certainly something I’m going to take seriously, and really look at it closely over the next month or two."

To be continued. And, knowing Christie's tendency to never let a slight go unanswered, it will be continued.

Update 12:54 p.m.: And here's Christie's rejoinder: