Because I believe the US never had and does not now have any such information - at least none that could be considered accurate or actionable. The entire proposition is a blatant fraud.
This claim is merely a ploy to confuse and distract Jews who may be wavering in their unconditional support for Democrats and the Biden administration. See, the Democrats offer something of value to Israel in exchange for a concession from Israel. What a deal!
So, keep those campaign contributions coming and tell everybody to vote for the Democrats this fall.
Tell a big enough lie and some people will always find "reasons" to believe it. The bigger the lie, the better this works. But even if people don't believe the lie, they may hesitate just long enough to prevent a decisive counteraction. And that is the whole point of the lie.
That's what I figured.