Can the US House compel a state prosecutor to provide documents about an upcoming state court case?

Question

The US House Judiciary Committee, Oversight Committee, and Administration Committee all sent a letter to Alvin Bragg, the current New York County District Attorney overseeing the New York "Hush Money" case against Trump, asking "to advance our oversight, please produce the following documents and information"...

1. All documents and communications between or among the New York County District Attorney’s Office and the U.S. Department of Justice, its component entities, or other federal law enforcement agencies referring or relating to your office’s investigation of President Donald Trump;
2. All documents and communications sent or received by former employees Carey Dunne and Mark Pomerantz referring or relating to President Donald Trump; and
3. All documents and communications referring or relating to the New York County District Attorney Office’s receipt and use of federal funds.

The letter claims...

Your decision to pursue such a politically motivated prosecution—while adopting progressive criminal justice policies that allow career “criminals [to] run[ ] the streets” of Manhattan —requires congressional scrutiny about how public safety funds appropriated by Congress are implemented by local law-enforcement agencies. In addition, your apparent decision to pursue criminal charges where federal authorities declined to do so requires oversight to inform potential legislative reforms about the delineation of prosecutorial authority between federal and local officials. Finally, because the circumstances of this matter stem, in part, from Special Counsel Mueller’s investigation, Congress may consider legislative reforms to the authorities of special counsels and their relationships with other prosecuting entities.

Pursuant to Rule X of the Rules of the House of Representatives, the Committee on the Judiciary has jurisdiction over criminal justice matters in the United States. The Committee on House Administration has jurisdiction over matters concerning federal elections. The Committee on Oversight and Accountability may examine “any matter” at any time.

It seems highly problematic for the US House to be intervening in a New York state criminal investigation, especially when no indictment has yet been made. Given that the letter cites such prestigious legal journals as the NY Post, Fox News, and The Daily Mail, I'm skeptical of their legal standing.

What happens if Mr. Bragg refuses? Can they compel him to produce these documents? If so, under what authority?

Answer 1

This recent SCOTUS ruling on a related matter sums up Congressional subpoena power, in holding (b):

Each House of Congress has the power “to secure needed information” in order to legislate. McGrain v. Daugherty, 273 U. S. 135, 161. This power is “indispensable” because, without information, Congress would be unable to legislate wisely or effectively. Watkins v. United States, 354 U. S. 178, 215. Because this power is “justified solely as an adjunct to the legislative process,” it is subject to several limitations. Id., at 197. Most importantly, a congressional subpoena is valid only if it is “related to, and in furtherance of, a legitimate task of the Congress.” Id., at 187. The subpoena must serve a “valid legis- lative purpose.” Quinn v. United States, 349 U. S. 155, 161. Furthermore, Congress may not issue a subpoena for the purpose of “law enforcement,” because that power is assigned to the Executive and the Judiciary. Ibid. Finally, recipients of congressional subpoenas retain their constitutional rights and various privileges throughout the course of an investigation.

The lower court found "that the subpoena issued by the Oversight Committee served a valid legislative purpose because the requested information was relevant to reforming financial disclosure requirements", but SCOTUS does not agree in that case that there is such a legislative purpose.

This is a summary of house and senate rules for issuing a subpoena, and here is a summary of the House procedure and legal framework for a resolution of contempt. It is not clear that a subpoena has been issued (per House rules), let us assume that at some point a subpoena is issued. Then Mr. Bragg might argue in court that the members of the House are not acting within a legitimate legislative sphere. The letter does not purport to intervening in a New York state criminal investigation, and the non-existence of an indictment is irrelevant.

Whereas in Trump v. Mazars there was a real separation of powers issue regarding the executive vs. legislative branch, the letter spells out the legitimate congressional interest at stake, which is that the investigation:

requires congressional scrutiny about how public safety funds appropriated by Congress are implemented by local law-enforcement agencies. In addition, your apparent decision to pursue criminal charges where federal authorities declined to do so requires oversight to inform potential legislative reforms about the delineation of prosecutorial authority between federal and local officials. Finally, because the circumstances of this matter stem, in part, from Special Counsel Mueller’s investigation, Congress may consider legislative reforms to the authorities of special counsels and their relationships with other prosecuting entities.

Answer 2

Regarding “What happens if Mr. Bragg refuses?”

Congressional subpoenas do not have much teeth. If a congressional subpoena is ignored (as Jim Jordan himself did in regard to a May 12 2022 subpoena) nothing happens unless the whole house votes a contempt resolution.

The Inherent Contempt of Congress where the Sargent at Arms drags the person into the chamber is no longer used. Under the Statutory Contempt of Congress (2 USC 192) Congress would need to rely on the DOJ to pursue the case.

In the recent past the DOJ has done so in only a few cases.