Why exactly has Devin Nunes gone all 'Jekyll/Hyde' over the Russia investigation?

If you had never heard of GOP House Intelligence chair Devin Nunes before he slipped off to his nighttime rendezvous at the White House last week then turned around the next day to deliver one of the most bizarre press conferences in recent memory, you're not alone. Before the Trump/Russia investigation, the California lawmaker was reportedly steadfast in his beliefs but relatively normal—which is probably why he wasn't much of a household name.

Nunes was tapped to lead the Intelligence Committee in 2015 by former House Speaker John Boehner and according to his Democratic colleague, Rep. Jackie Speier, he used to be a relative joy to work with on the panel. All that changed during the Trump/Russia investigation. "That's what's so interesting," Speier told MSNBC Wednesday, when asked what the pre-Trump Nunes was like.

He was easy to work with. It was a bipartisan committee. We worked closely together. It's like a Dr. Jekyll/Mr. Hyde that has taken place here. He is different. He has become pugnacious and silent and surreptitious and all the sudden he is not consulting with the ranking member in terms of having a hearing, not having a hearing. And all the sudden we're reading about it in the press.

So one has to wonder: What turned cooperative, easy-to-work-with Devin Nunes into sneaky, evasive, "I'm not telling" Devin Nunes? How did he become someone who reportedly got tipped off to information by the White House on March 21 in the dead of night, then returned the next day to supposedly brief the president on what he had learned from his White House sources? (Good Nunes timeline here.) All this without informing his committee colleagues in advance of information that he still hasn’t fully disclosed to them.

It's worth noting here that Nunes worked on the Trump transition team. He also went to bat in multiple news outlets last November for now-resigned Michael Flynn when Flynn was first named Trump's national security adviser.