The Supreme Court’s 5-4 ruling in Citizens United vs. the FEC lifted restrictions on companies, unions, and other organizations, allowing them to make independent expenditures in political campaigns.
That ruling, however, did not allow corporations to contribute directly to a campaign or to coordinate expenditures with a campaign. Nor did the ruling lift existing law that blocks foreign contributions to political campaigns.
Under the FEC regulation 11 CFR 110.20(i): “A foreign national shall not direct, dictate, control, or directly or indirectly participate in the decision-making process of any person, such as a corporation, labor organization, political committee, or political organization with regard to such person's Federal or non-Federal election-related activities, such as decisions concerning the making of contributions, donations, expenditures, or disbursements in connection with elections for any Federal, State, or local office or decisions concerning the administration of a political committee.”
Further, federal law, under 2 USC 441-Sec. 441e, also prohibits foreign donations to political campaigns.