Never can there come fog too thick, never can there come mud and mire too deep to assort with the groping and floundering condition which this High Court of Chancery, most pestilent of hoary sinners, holds this day in the sight of heaven and earth.
Translation:
In the sight of heaven and earth, the floundering and groping condition this High Court of Chancery has is so bad it cannot be classified with the thickest fog or the deepest mire and mud.
floundering and groping makes one think of a person who is sinking and cannot swim. Think of a person who falls in the water and cannot swim. It is the metaphor for a person who cannot control his/her body.
The difficulty, in my view, for a non-native speaker is the idea of:
The High Court of Chancery holds a condition in the sight of heaven and earth.
The verb hold there just means "has".