Donald Trump, the 73-year-old president, often repeats himself. Braulio Carrero, my doctor, explains that after the age of 70, it is common for memory to begin to fail.

Ronald Reagan was 73 years old when he ordered the sale of weapons to Iran in order to finance the Nicaraguan Contras. He denied having done so, because he’d forgotten that he’d done it. The Alzheimers that eventually took his life began by erasing his short-term memory.

Former Vice President Joe Biden, the current leader of the Democratic presidential hopefuls, will be 78 years old in 2021, and is already showing signs of serious memory slips.

The United States’ presidential options are white septuagenarians with failing memories.

In 2021, Trump will be 74, Biden 78, Sanders 79, and Warren 71.

These are the white options, and it seems the white norm isn’t allowing black or Latino candidates. This racism is potentially catastrophic.

The issue is larger than Trump, larger than Republicans and Democrats. It poses a threat for us all. A U.S. president who is losing his or her memory can cause serious problems for global security.