In 1909 former professional baseball player turned politician John Tener, a congressman who would later become Governor of Pennsylvania, proposed a casual baseball game between House Democrats and Republicans.  Nearly every year since, the baseball game has taken to a local ballpark so Congress can settle their differences with bats and balls instead of gavels and filibusters. 

Wednesday's shooting of Congressman Steve Scalise, at a practice before the game, brought global attention to what's typically a date only in US politicians' calendars. The 2017 game is scheduled for Thursday June 15, and soon after Wednesday's shooting, California Republican Eric Swalwell said in a Tweet that it would go ahead as planned. 

A friendly, but still partisan game

In a 2012 interview, former Republican representative Michael Oxley of Ohio said the members of Congress who play in the annual game are "part of a fraternity that is everlasting."

"It's kind of frivolous, but at the same time it's something that connects everybody whether you're Republican or Democrat," said Oxley.

The game has been held most every year since 1909, and became a firm, yearly tradition since 1962. Between 1935 and 1941, Democrats and Republicans would team up to play against members of the press.

The game has usually taken place at the closest professional baseball ballpark to Congress and now takes place at Nationals Park, home of the Washington Nationals. Most Congressmen practice just a few times before the real thing. Congressional staff, family and friends are usually in attendance. Even the crowd is split along party lines, with Democrats down the left field line and Republicans down right field. Ticket sales go towards local charities.

The game is open to the Senate as well, ever since Washington state's Senator Henry Cain played as the starting pitcher for the Republicans in 1950. Congresswomen are also allowed to play, two of them did so for the first time in 1993. 

Overall, Republicans hold a 42-38-1 advantage over Democrats. The 1983 game was called after it was tied following the standard nine innings. Most professional baseball games would go to extra innings to settle the result.