Consider this:
The United States Senate Committee on Homeland Security and Governmental Affairs is the chief oversight committee of the United States Senate. It has jurisdiction over matters related to the Department of Homeland Security and other homeland security concerns, as well as the functioning of the government itself….. It serves as the Senate's chief investigative and oversight committee. Its chair, Republican Senator Ron Johnson has incredible power not only because of the importance of this committee but because this is the only Senate committee whose chair who can issue subpoenas without a committee vote. Wikipedia
There are several high profile Republicans who are members including Rand Paul who often marches to the beat of a drummer only he hears. The highest profile Democrat on the committee is Sen. Kamala Harris:
Now consider this:
Yesterday Sen. Johnson on Fox News called out the Department of Justice, Trump’s DOJ under his lackey William Barr, for not responding to domestic terrorism questions:
Excerpt from Think Progress: Senate Republican calls out Trump’s DOJ for not responding to his domestic terrorism questions
Sen. Ron Johnson (R-WI), chairman of the Senate Homeland Security and Governmental Affairs, is typically a loyal ally of President Donald Trump and his administration. But on Wednesday, he went on Fox News and scolded Trump’s Justice Department and FBI for failing to provide even basic information about a major domestic terrorism threat.
In early May, Johnson and the committee’s top Democrat — Sen. Gary Peters (D-MI) — authored bipartisan letters that were sent to Kevin McAleenan, the acting secretary of Homeland Security, Attorney General William Barr, and FBI Director Christopher Wray. These letters asked for information about domestic terrorism and how each is addressing it. DHS responded, but four months later, the Justice Department and the FBI — which operates within the DOJ — have not.
In a new letter on Monday, Johnson and Peters noted that there have been several domestic terrorism attacks since their first letter. “Since the date of our request, there have been numerous mass attacks, including Virginia Beach, VA; Gilroy, CA; El, Paso, TX; and Dayton, OH… These continued mass attacks make it clear that the federal government has more work to do in preventing domestic terrorism.”
Trump may have missed this even though the interview, which you can watch on Think Progress, appeared on Fox News. Therefore this may fly under his radar as a threat that he ought to pay attention to because it is possible, just possible, that Sen. Johnson is actually a patriotic American who believes that domestic terrorism is a serous threat despite what Trump thinks.
He may not say violent white nationalism but he knows that the terms are interchangeable with domestic terrorism. He’s well aware that there is no threat to the homeland from a Zodiac full of liberal Green Peace protestors.
Trump may be worried about the Democratic controlled House and its committees as they pursue numerous investigations. He may be uneasy in his ignorance and mixed messages no doubt he gets from his allies about what effects a formal impeachment proceeding would have on his fate prior to or following the election.
Trump probably feels protected by Moscow Mitch but from what I gather if he choose to go his own way Sen. Johnson could defy the increasingly beleaguer Kentucky majority leader. Johnson was elected for his second term in 2016 in Wisconsin where Trump unexpectedly won by a narrow margin of 0.77%, with 47.22% of the total votes over the 46.45% of Hillary Clinton. He won’t have to run in 2020 so he doesn’t have to worry about the Trump base until then. Plus it may not even exist in Wisconsin even if the president wins a second term.