The answer is to maintain the keys to power. Most politicians end up getting cocky after being in office for years and make mistakes. But the one exception to this rule is in Singapore.
PAP has remained in power in Singapore since independence. From a fairly lazy point of view one might assume this is because the elections is rigged, but in reality there is no sign the election was rigged. PAP has remained in power for 50 years because they consistently deliver results. Singaporeans have a high quality of life. They have the highest GDP per capita in the world. Things are stable. We find a similar pattern in Luxembourg where CSV has remained in power for 35 of the last 45 years. CSV has also led their country in a way towards prosperity with strong social programs.
One important difference is that Luxembourg consistently has coalition governments like most countries in Europe. Unlike others however rule has stayed pretty consistently in the hands of CSV. It literally took a spy scandal for them to lose power in the 2013 election.
Germany is similar. Merkel stayed in power in Germany until she resigned as party leader. SPD was unable to pull together a strong leader against her during her time in office, and the economy remained strong aside from the global 2008 recession. She also led a coalition in each of her governments, with the SPD three times and FDP once. Her party remained the strongest party in the Bundestag for 16 years.
This is true in every democracy really. Keep the economy strong. Don’t mess up foreign policy. Don’t have a scandal. If you do these three things you will probably stay in power.
For this reason we can explain every time parties lost power in American history. A similar analysis can be done for every democracy.
Why the presidency changed hands
2024 is because of the wars in Gaza and Ukraine.
2020 is because of the COVID-19 pandemic
2016 is because of the Electoral College. Obama did a good job and Clinton beat Trump by millions of votes.
2008 is because of the 2008 recession.
2000 is because of the Electoral College. Clinton presided over a strong economy with no major foreign policy mistakes, so Gore won the popular vote.
1992 is because of Ross Perot.
1980 is because of the Iran Hostage Crisis
1976 is because of Watergate
1968 is because the Vietnam War was in a stalemate.
1960 is because of Cuba’s fall to communism and an ongoing recession.
1952 is because of crises in Korea and the fall of China.
1932 is because of the Great Depression.
The list continues.
So this means that if presidents were able to avoid making major screw ups, the presidency would change a lot less often.
Abolishing the electoral college would also help based on the result of the 2016 election.
I do not believe stability of one party staying in power is the clear benefit. But keeping extremists like Trump out of office is an obvious benefit to our country. Abolishing the electoral college will help keep extremists out of the presidency.
Adopt a modern election system, keep a strong economy, and don’t screw up foreign policy to keep power.