In baseball, it's called "The Mendoza Line," a low-water mark named after anemic-hitting Pittsburgh Pirates and Seattle Mariners' shortstop Mario Mendoza.

Mendoza struggled to keep his batting average above .200.

Players whose average dips to near .200 are said to be flirting with "The Mendoza Line."

There's a Mendoza Line in the House of Representatives, too. Also positioned at 200.

The number 200 is a psychologically important figure in the 435-member House. And contingent on projections, it appears as though Democrats are headed south of the Congressional Mendoza Line, too.

Republicans were well below it at different points during this Congress. They currently hold just 178 House seats.

Democrats only dipped below the 200-seat mark a couple of times after the GOP seized the majority in 1994. And that only came after a few conservative Democrats jumped ship and joined the GOP.