Bad enough that the Senate became a theatre of venomous invective — in which, it must be conceded, Mr. Sumner is one of the adepts. But it is a humiliation, an offence to the whole country, that its sanctity should be so ruthlessly violated by the scene Mr. Brooks enacted.
Original passage & context
"It was bad enough that that hall should have been permitted to become the theatre of venomous invective and personal defamation between members, and that the tone of the public discussions there held should have been so lowered as we find them of late, (and in which, it must be conceded, Mr. Sumner appears as one of the adepts;) but it is indeed a humiliation and a degradation -- an offence, too, as it were to the whole country -- that its sanctity should have been so ruthlessly violated by such a scene as that enacted by Mr. Brooks."
Border-state moderate voice: one sentence performing the whole blame-distribution move — Sumner an 'adept' of invective in a parenthetical, Brooks's act the greater violation of the chamber's sanctity.
Read it in the original — Furman Secession Era Editorials transcription ↗