For the purposes of election related fund raising and spending, define any US based company, corporation or group that this a subsidiary of a foreign company as a non-US entity.
Currently, foreign companies are prohibited from spending in US elections, but their US subsidiaries are not. Close this loophole and eliminate the potential of foreign companies (or countries) from influencing our elections. This has the added benefit of getting more corporate money out of the system.
A hidden benefit could be that if a company really wanted to spend in elections, they would have to reincorporate in the US, and by extension start paying more taxes here.