Mike Pence did a dumb thing in Arizona. And, yes, Joe Arpaio was involved.

"A great friend of this president, a tireless champion of strong borders and the rule of law," Pence said. "Sheriff Joe Arpaio, I'm honored to have you here."

There are a few things wrong with that statement by Pence.

First, the idea that Arpaio is a "tireless champion ... (of) the rule of law" is provably false.

In 2011, a federal judge ordered Arpaio to stop stopping anyone who was not directly suspected of having committed a state or federal crime. (The lawsuit came as the result of the 2007 detention of a Mexican man who had a tourist visa.) Arpaio never acknowledged that order and continued on enforcing his own brand of immigration policy. He was found guilty of criminal contempt and was scheduled to be sentenced last fall -- just as President Donald Trump stepped in and pardoned the controversial sheriff.

So, no, he is not a champion for the rule of law. He is a champion for the law as he decides it to be. Which is not the same thing.

Then there is the political dumbness of Pence's praise of Arpaio.

At the moment, Arpaio is one of three major candidates running for the Republican Senate nomination on August 28. (The seat is open due to GOP Sen. Jeff Flake's retirement.) Arpaio is widely regarded as the weakest of the three candidates -- and someone who would begin well behind likely Democratic nominee Rep. Kyrsten Sinema.

The limited polling in the Republican primary shows Rep. Martha McSally with a clear edge but former state legislator Kelli Ward and Arpaio are still very much in contention.

An endorsement like the one Pence gave Arpaio in Tempe on Tuesday is just the sort of thing the 85-year-old former sheriff needs to build some momentum. If he is smart, he will put that Pence line of praise in every single TV and radio ad he runs between now and the end of August.

While Trump (and, by extension, Pence) are not super popular in the whole of Arizona, the President and his vice president remain very popular figures within the Republican primary electorate. If Arpaio can position himself as the Trump candidate -- and the President has praised him, too -- it could give the controversial sheriff a real chance at the nomination.

Which would be a disaster for Republicans clinging to a one-seat margin in the Senate. Arizona is one of only three GOP-held seats the party has to defend this November -- and it can't afford to lose it before the general election even starts.

Mike Pence knows all of that. Which makes his praise of Arpaio all the more baffling.