Form Kahls bio on Wikipedia:
In the Obama administration, Kahl was directly involved in negotiating the Iran Nuclear Deal, as well as publicly advocating for it.
In May 2018, it was revealed that aides to U.S. President Donald Trump had contracted with Israeli private intelligence firm Black Cube to find evidence to support unsubstantiated and false claims that Kahl was being enriched by Iran lobbyists and that either he or Deputy National Security Advisor Ben Rhodes were cheating on their wife.
Kahl has most likely already been investigated by the Trump FBI and found innocent, which Im sure these Republicans know, but this is simply a delaying tactic to which I hope Schumer gives no credence. And is it a coincidence that this request has been made after last weekends meetings at Mar-a-Lago where Republicans bowed to their master? Or a coincidence that Israel just sabotaged Iranian facilities? They could have been acting on their own, but such serious actions should be at least discussed with the US government. No one in the Biden administration would have given a go ahead, so is Netanyahu still taking orders from Trump/Kushner?
For whatever reasons, Trump still has a big hold on Republican legislators. He, and they, are not a risk to be ignored.