20.1
The section consists of two sentences:
a. exim ... elati;
b. una ... agerentur.
They feature more or less parallel syntax: in each case, a main clause (exim ... agitur; una ... penetraverat) is followed by a sequence of subordinate clauses. In thematic terms, however, the design is obliquely asymmetrical. The first main clause sets up the entire scene, whereas the second main clause harks back not to the first main clause (its apparent syntactic counterpart) but to the subordinate constructions that follow it: una vox correlates antithetically with ceteris criminibus. The design downplays the generalizing cetera crimina: they are awkwardly tagged on in an ablative absolute and further elaborated in an elliptical ut-clause, in contrast to the one specific vox, which is the subject and in first position. Sandwiched as they are between two main clauses that lead from the introduction of the defendant to the one offence (the una vox) that brought him to the attention of the senate, they are syntactically glossed over.
20.4
After setting out and illustrating his principles, Thrasea proceeds to outline a course of action. He would like a decision that (a) checks further haughty behaviour on the part of provincials, i.e. is directed adversus novam provincialium superbiam; but also (b) meets Roman standards of excellence in terms of fides and constantia (dignum fide constantiaque Romana capiamus consilium). Both terms find further elaboration in the quo-clause: fide is picked up by quo tutelae sociorum nihil derogetur; and constantia by [quo] nobis opinio decedat, qualis quisque habeatur, alibi quam in civium iudicio esse. The -que after constantia, which links fide and constantia, is the first (!) connective in Thrasea’s speech, but he instantly falls back into asyndetic mode. The two parts of the quo-clause (...derogetur, ... decedat) are unlinked, continuing the terse, unremitting, to-the-point accounting and enumeration that is a hallmark of the speech from the outset.