How to limit foreign meddling in US campaigns has been very topical since 2016. Several solutions have been advanced. The latest proposals on this front come from Brennan Center For Justice. The article states that:

Americans are concerned about the continuing threat of foreign interference in U.S. elections. Although Russia’s 2016 exploits have received much attention, intelligence agencies and national security experts warn that we are likely to face additional interference in our elections from a greater number of adversaries going forward. What can be done? There is no silver bullet. Tackling this problem requires a range of nuanced solutions that simultaneously preserve the integrity of U.S. elections, protect the constitutional rights of all Americans, and leave sufficient room for beneficial international exchanges. In this analysis, we detail a menu of key recommendations to combat illicit foreign meddling in U.S. campaigns. Together with measures to reinforce the security of our election infrastructure, we believe these reforms will go a long way towards reinforcing U.S. sovereignty in a manner consistent with bedrock American values.

 Read the full article here for an overview of the reforms that should be implemented to limit foreign interference.