Washington (CNN) Amid widespread uncertainty over what Washington will do about guns in the wake of the Parkland, Florida, school shooting that left 17 people dead, Donald Trump grabbed the presidential mantle with a series of tweets on ... Russia.

Well, not Russia exactly. More like on special counsel Bob Mueller's investigation into Russia's attempts to meddle in the 2016 election and potential collusion with the Trump campaign.

The President, as you might have guessed, is not a fan.

Catching up on taped Fox News programming on Tuesday morning, Trump rapped out quotes from former independent counsel Ken Starr and George Washington University law school professor Jonathan Turley that rejected the idea of any sort of collusion between the President's campaign and Russia.

"I've been skeptical about the collusion and obstruction claims for the last year. I just don't see the evidence....in terms of the collusion, it's all a bit implausible based on the evidence we have." Jonathan Turley on @FoxNews

Then Trump went simpler, with just a two-word tweet: "WITCH HUNT!"

Trump, without a scheduled event until 11 am, appeared to be engaging in some so-called "executive time" where he watches cable TV -- often programs he has taped -- and tweets occasional thoughts about them.

As always, when the President takes to Twitter, it's very much worth paying attention to. After all, Trump's Twitter feed -- as I have argued before -- is the best window we have ever had into what the nation's most powerful person is thinking and doing at any given moment.

The Twitter feed is pure Trump -- unadulterated by the voices of his staff or any other better angels. It's what he thinks about and what he cares about -- simple and plain.

And, on this morning -- as on so many mornings before it -- that was the ongoing Russia probes.

What it wasn't was the debate over gun safety and what measures -- if any -- the Republican-led House and Senate will take up in the coming days or weeks aimed at addressing things like expanding background checks or raising the age to buy a rifle from 18 to 21.

He might like to get something done on guns, but he's relatively agnostic as to what that is. He'd like to sign something, to notch a victory, to get gun legislation passed in the wake of a school shooting -- unlike President Barack Obama following the murders at Sandy Hook elementary school.

But that debate is not what animates Trump, not what gets his juices flowing.

What drives Trump -- at least judging by his tweets -- is a deep-seated belief that the entire Mueller investigation is nothing more than the result of Democrats, unhappy with the 2016 election results, trying to discredit him.

Worth noting: Bob Mueller was named FBI director by Republican President George W. Bush. Rod Rosenstein, who appointed Mueller as special counsel, is a Republican appointee -- named to his job by Attorney General Jeff Sessions. The congressional committees looking into the Russian involvement are all controlled by Republicans.

Trump likely knows all of this. And doesn't care. In his mind, all of this Russia talk is simply the result of haters and losers who can't deal with the fact that he won fair and square in 2016.

That focusing on Russia again and again and again in tweets complicates Trump's ability -- and willingness -- to be an effective leader on other issues, like guns.

Republican leaders in Congress are desperately looking to the White House for some sign of what his priorities are when it comes to guns. The signal Trump sent with his series of Russia tweets on Tuesday morning is that he is just not focused on guns at all.

Simply put: Trump is driven to distraction by the Russia investigation. He proved that, again, on Tuesday morning.