Short answers, pulled from the story.
The 2020 amendments are the second substantial revision to Russia's 1993 Constitution, proposed by President Vladimir Putin in January 2020. In total, 41 articles were rewritten and five more were added, altering around 60% of the Constitution's alterable articles. They were approved by a national vote on the 1st of July 2020 and took effect on the 4th of July.
Under Point 3 of Article 81, the same person could not serve as president for more than two consecutive terms. Putin, elected in 2012 and re-elected in 2018, would have been barred from running in 2024. The amendments removed the "in a row" phrase from the term limit clause and nullified all presidential terms served before the changes came into force, resetting his count entirely.
In its opinion published on the 23rd of March 2021, the Venice Commission concluded the amendments disproportionately strengthened the president's position and dismantled checks and balances. It found that empowering the president to initiate dismissals of apex court judges on vague grounds was a danger to the rule of law. The Commission also found the speed of adoption clearly inappropriate given the depth and societal impact of the changes.
A national vote was held on the 1st of July 2020, with early voting from the 25th of June, after being postponed from April due to the COVID-19 pandemic. With 98% of the ballot counted, 78% voted in favor and 22% against. The format differed from a standard referendum, with no minimum turnout requirement and only one month of preparation time instead of the standard 90-100 days.
Presidential candidates must now have lived in Russia for at least 25 years, up from the previous ten. Holding foreign citizenship or residency at any point in one's life is permanently disqualifying, with no possibility of renouncing foreign citizenship to become eligible.
On the 16th of March 2020, 128 Russian lawyers, political scientists, and human rights defenders petitioned the Council of Europe, and the petition gathered over 200,000 signatures on Change.org by the 27th of May. The Guardian described the amendments as initially seen as a way for Putin to retain power past 2024. Scholar Will Partlett characterized them as "theatrical constitution-making" used to support authoritarian populism.