FEDERAL OFFICIALS DO NOT STOP ELECTION CRIMES before or during elections. Their policy is to investigate and they may prosecute after elections. The Justice Department has published Federal Prosecution of Election Offenses in eight editions from 1976 to 2017, under Presidents Ford, Carter, Reagan, Clinton, Bush and Trump. The link compares six of the editions which are online.
Sentencing guidelines are too light to deter major fraud. Election offenses start at "level" 8 to 14, which give prison terms for a first offender of 0-21 months and a $2,000-$75,000 fine. Sentences can be adjusted up or down depending on circumstances.
Federal officials pretend that defenses are effective, even when many states do not audit. They also hide actual attacks by hackers: Florida registrations, VR Systems (election night reporting and voter lists), Russian ownership of election web host (minute 6:54 of video), August 2016 email to states (pp.146-151), etc. States ignored the August and October 2016 warnings, because states are used to internet scanning; federal officials did not say this scanning was from a nation state, and could not answer questions (pp.49,51 of Senate report)