"Sorry, Democrats, but America is unlikely to have a Democratic president before 2025...."

"[I] you look at historical patterns from the end of the 19th century to now, you’ll see that a party (Republican or Democratic) almost always holds the presidency for at least 8 years. Notice I’m saying a 'party,' not a 'president.' For example, Ronald Reagan was a Republican president for 8 years, followed by another Republican president, George H.W. Bush, for 4 years; that’s 12 continuous years of Republicans, so that whole time follows the 8-year minimum rule, even though one of those presidents was in office for only 4 years. There’s been only one exception since 1897 (when the first 20th-century president took office).... Jimmy Carter...."

Writes my son John (at Facebook).

It sounds like a very strong rule, but there is that one exception.