(NewsNation) —  Gerontocracy: A state, society or group governed by old people.

The Oxford Dictionary definition sums up much of the world these days. Eight of the planet’s largest countries are led by people aged 70 or older. And the two that don’t – Indonesia and Pakistan – will have septuagenarians in charge soon.

In much of the world, the boom in boomers running the show has to do with autocrats tightening their grip on power over the years.

Russia’s Vladimir Putin first became president at age 47 and has remained in power for nearly 25 years. China’s Xi Jinping is in his third term as president at age 70.

And, of course, the race for President of the United States comes down to 81-year-old incumbent Joe Biden against 77-year-old former President Donald Trump.

One reason many world leaders are still leading is the power of incumbency. When winning elections requires tens of millions of dollars, established politicians with extensive donor networks have the advantage.

Last year the Pew Research Center asked Americans: does it matter? The Chicago Council on Global Affairs asked a similar question in 2022. Both surveys concluded that, while most Americans would support an upper age limit for federal elected officials, it’s not their top consideration when deciding who to vote for.

A 2022 Business Insider poll ranked age as the sixth-most important factor in voters’ evaluation of candidates, behind issues, experience, health, political party and education.

Efforts to cap the age of candidates have never gotten very far.

Last year, Rep. John James, R-Mich., proposed a constitutional amendment to bar anyone who would turn 75 during their term from running for president or Congress, but the House never considered it.