Could Nordstrom invoke the UCL over a Trump tweet?

I was asked this question today by a Politico reporter, and was subsequently quoted in his article, "Trump blasts Nordstrom for dropping Ivanka's clothing line." 

Although I have other serious concerns about this type of tweet by a sitting president, I have a hard time seeing a UCL claim for Nordstrom in this fact pattern.   The article sums up why.   (Welcome, Politico readers!)