When a gunman ambushed a practice for a charity congressional baseball game in Alexandria, Va., on Wednesday, at least five people were injured. And, witnesses have suggested, that number might have been higher had members of the U.S. Capitol Police not been there — as part of House Majority Whip Steve Scalise's security detail — to fire back.

"Without the Capitol Hill police, it would have been a massacre," Kentucky Republican Senator Rand Paul told the press.

As some speculate about whether partisan politics motivated the gunman — who reportedly asked one of the congressmen if Democrats or Republicans were playing — it can be noted that the U.S. Capitol Police force, which is charged with protecting Congress, was established after one particular assault that took place in the polarized political climate that was 1828.