From p. 14 of the slip opinion:

Taking into account the text of the statute, the precedent of this Court, and the constitutional concerns raised by Governor McDonnell, we reject the Government’s reading of §201(a)(3) [the federal bribery statute] and adopt a more bounded interpretation of “official act.” Under that interpretation, setting up a meeting, calling another public official, or hosting an event does not, standing alone, qualify as an “official act.”

From pp. 21-22:

[A]n “official act” is a decision or action on a “question, matter, cause, suit, proceeding or controversy.  The “question, matter, cause, suit, proceeding or controversy” must involve a formal exercise of governmental power that is similar in nature to a lawsuit before a court, a determination before an agency, or a hearing before a committee. It must also be something specific and focused that is “pending” or “may by law be brought” before a public official. To qualify as an “official act,” the public official must make a decision or take an action on that “question, matter, cause, suit, proceeding or controversy,” or agree to do so. That decision or action may include using his official position to exert pressure on another official to perform an “official act,” or to advise another official, knowing or intending that such advice will form the basis for an “official act” by another official. Setting up a meeting, talking to another official, or organizing an event (or agreeing to do so)—without more—does not fit that definition of “official act.”

And from p. 28:

There is no doubt that this case is distasteful; it may be worse than that. But our concern is not with tawdry tales of Ferraris, Rolexes, and ball gowns. It is instead with the broader legal implications of the Government’s boundless interpretation of the federal bribery statute. A more limited interpretation of the term “official act” leaves ample room for prosecuting corruption, while comporting with the text of the statute and the precedent of this Court.