House Intelligence Committee chairman Adam Schiff (D-CA) responded to Rep. Devin Nunes’ (R-CA) witness requests Saturday, saying that he would not allow the impeachment inquiry to become a “vehicle” for more “sham investigations.”

Nunes, ranking member on the committee, sent his list in a letter to Schiff earlier on Saturday, naming the whistleblower and Hunter Biden among the people Republicans want to testify.

Schiff responded in a statement, saying that he would give the request “due consideration.”

“This inquiry is not, and will not serve, however, as a vehicle to undertake the same sham investigations into the Bidens or 2016 that the President pressed Ukraine to conduct for his personal political benefit, or to facilitate the President’s effort to threaten, intimidate, and retaliate against the whistleblower who courageously raised the initial alarm,” Schiff wrote.

Republicans have been struggling to distract from the damning fact pattern established by most of the impeachment witnesses so far, complaining about the private testimonies and accusing Democrats of a lack of transparency. Since that argument will be moot next week as the public hearings begin, Republicans like Nunes seem to be casting about for a new angle rooted in the baseless conspiracy theory President Donald Trump has tried to propagate about Hunter Biden’s involvement with a Ukrainian company.