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This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

In May 1955, McCarthy threatened to issue subpoenas to White House personnel. Eisenhower was furious, and issued an order as follows: "It is essential to efficient and effective administration that employees of the Executive Branch be in a position to be completely candid in advising with each other on official matters ... it is not in the public interest that any of their conversations or communications, or any documents or reproductions, concerning such advice be disclosed." This was an unprecedented step by Eisenhower to protect communication beyond the confines of a cabinet meeting, and soon became a tradition known as executive privilege. Ike's denial of McCarthy's access to his staff reduced McCarthy's hearings to rants about trivial matters, and contributed to his ultimate downfall.
Output:
What did McCarthy threaten to do in May of 1955?