1. When a defendant makes false statements to a United States Attorney's Office in an effort to persuade that Office to decline prosecution, does the objective institutional relationship of that Office with the grand jury satisfy the "nexus" required for obstruction or attempted obstruction of a grand jury proceeding under 18 U.S.C. § 1512(c)(2), regardless of whether the defendant subjectively knew, understood, or believed the false documents would be given to the grand jury?

2. When a prosecutor commits misconduct in summation by misstating evidence relevant to an essential element of the offense, but the defendant fails to object, does the fact that the district court provided the jury a standard instruction that "arguments are not evidence" necessarily preclude reversal on appeal for plain error based on the prosecutor's misconduct?

When does the 'nexus' requirement for obstruction of an official proceeding under 18 U.S.C. § 1512(c)(2) apply when false statements are made to a U.S. Attorney's Office?