Now that a formal impeachment inquiry is underway and being conducted by three House committees (Intelligence, Judiciary, and Oversight), congressional investigators have the right to virtually any evidence or testimony they say it pertinent to the case they’re building against President Donald Trump.

And since we know that Trump tried to extract concessions from Ukrainian President Volodymyr Zelensky in exchange for hundreds of millions of dollars in U.S. military aid, it appears that part of the impeachment inquiry will include a closer look at Trump’s calls with Russian President Vladimir Putin.

House Intelligence Committee Chairman Rep. Adam Schiff (D-CA) said recently on “Meet this Press” that his committee would indeed be seeking to find out what Trump discussed with Putin:

“The paramount need here is to protect the national security of the United States and see whether, in the conversations with other world leaders and, in particular, with Putin, that the president was also undermining our security in a way that he thought would personally benefit his campaign.

“If those conversations with Putin or with other world leaders are sequestered in that same electronic file that is meant for covert action, not meant for this, if there’s an effort to hide those and cover those up, yes, we’re determined to find out.”

That could be very bad news for Trump, who has a bizarre fascination with and man crush on Putin. The two have often exchanged pleasantries and compliments with each other, with Trump even going so far as to say that since Putin assured him Russia didn’t interfere in the 2016 election, he believes him instead of U.S. intelligence agencies.

A full examination of all Trump’s calls with Putin might just be the evidence which proves a larger conspiracy between the two leaders. It has long been speculated that involves damaging information (“kompromat”) Putin has on Trump. That was one of the things investigated by Special Counsel Robert Mueller, who didn’t have the advantage of seeing Trump’s communications with the Russian leader.

The circle is starting to tighten around Donald Trump. With each day, it becomes clearer that he has something to hide. Once those secrets are exposed, it should be clear to everyone that the current president is a danger to the national security of the United States.