I absolutely agree with you regarding the need to send a message through an overwhelming landslide in the popular vote. The Pledge to Safeguard the Election (https://www.thepledge.site/pledge-to-safeguard-the-election) is a backup to counter electoral fraud by digging deeper into the grit of the electoral process to make sure that electoral officials follow the same rules that have been applied to previous modern elections. The stronger the victory in the popular vote, the less likely it will move to a post-election process and the easier it will be to deal with it.
Cast your votes on the House and local levels with it mind that these offices will have an effect on the presidential outcome if it goes as far as the House of Representatives. Follow through AFTER the election to make sure normal electoral processes are followed by keeping pressure on electoral officials of all kinds at all levels. We need to act NOW during this election (which might extend until January under the worst-case scenarios). If mail-in ballots are challenged, the results are closer than expected and President Trump then begins to manipulate the electoral college or attempts to move the process to the House, we will indeed begin moving towards authoritarianism.
A fuller explanation of The Pledge to Safeguard the Election can be found in the Medium ILLUMINATION-curated articles “Stop the Coming Election Crisis” (https://medium.com/illumination-curated/sign-the-pledge-to-safeguard-the-election-b4daae7efd93) and “Wake Up America! What if Trump Loses the Election and Really DOES Refuse to Go Peacefully?” (https://medium.com/illumination-curated/a-call-to-safeguard-the-election-3a81c9192071?
That we’re even questioning a peaceful transfer of power should be a deal-breaker with any candidate raising the question.