The Millionaires' Amendment mandates that once a self-financed candidate spends more than $350,000 of his personal funds on a campaign, his opponent may be permitted (1) to receive contributions at three times the limit for each donor that would otherwise be in place,
2 U.S.C. § 441a–1(a)(1)(A); (2) to receive contributions from individuals who have reached what would otherwise be their statutory limit for aggregate campaign donations,
id. § 441a–1(a)(1)(B); and (3) to coordinate with their political party on additional party expenditures that would otherwise be limited,
id. § 441a–1(a)(1)(C). To take advantage of those benefits, the opponent of a self-financed candidate must first calculate the “opposition personal funds amount” (“OPFA”) to determine whether he is eligible for relaxed limits on fundraising.
Id. § 441a–1(a)(1). To calculate the OPFA, the opponent determines the amount of personal funds spent by each candidate
(i.e., the self-financed candidate and himself), adds 50% of the total funds raised by each candidate during the year prior to the election, and compares the totals.
Id. § 441a–1(a)(2). If the opponent's OPFA is above that of the self-financed candidate, he may not take advantage of the relaxed limits and coordinated expenditures. If it is not, then he may take advantage of the relaxed limits, but only until parity is achieved under the OPFA formula. Once each candidate's OPFAs are equal, the Millionaires' Amendment no longer applies, and the opponent of the self-financed candidate cannot take advantage of the relaxed limits on contributions and coordinated expenditures.
Id. § 441 a1 (a)(3)(ii).