13 may not limit contributions to a non-profit that only makes expenditures.8 The Court reinforced those principles a year later in Citizens Against Rent Control. There, the Court struck down limits on donations to a non-profit committee seeking to defeat a ballot measure. See Citizens Against Rent Control, 454 U.S. at 296-99. Building on the established right of individuals to make unlimited expenditures, the Court stated that there are “of course, some activities, legal if engaged in by one, yet illegal if performed in concert with others, but political expression is not one of them.” Id. at 296. The Court further reasoned: “Placing limits on contributions which in turn limit expenditures plainly impairs freedom of expression.” Id. at 299. In the Court’s words, to place “a Spartan limit – or indeed any limit – on individuals wishing to band together to advance their views on a ballot measure, while placing none on individuals acting alone, is clearly a restraint on the right of association.” Id. at 296. 8 In Cal-Med, there was no majority opinion on the First Amendment issue. Under the Marks principle, Justice Blackmun’s opinion in Cal-Med appears to be controlling. See Marks v. United States, 430 U.S. 188, 193 (1977); cf., e.g., Regents of Univ. of Cal. v. Bakke, 438 U.S. 265, 269-320 (1978) (opinion of Powell, J.). Even if Justice Blackmun’s opinion were not binding under the Marks principle or even if his discussion of expenditure-only nonprofits were considered dicta, his opinion’s principles have been followed in subsequent decisions such as Citizens Against Rent Control. In that regard, we note that Justice Marshall’s opinion in Cal-Med did not decide how the First Amendment applies to contributions to a non-profit that only makes expenditures. See Cal-Med, 453 U.S. at 197 n.17 (opinion of Marshall, J.) (“American Civil Liberties Union suggests that § 441a(a)(1)(C) would violate the First Amendment if construed to limit the amount individuals could jointly expend to express their political views. We need not consider this hypothetical application . . . .”).