I've been reading an interesting book lately, Rhetoric at Rome; A Historical Survey by M.L. Clarke. Here are some highlights from chapter IV- Roman Oratory Before Cicero:
The age of the Gracchi, with its clash of ideals and personalities, was conducive to high and excited political oratory. The two brothers were famous for their eloquence; Cicero, in spite of his disapproval of the uses to which it was put, cannot forbear to praise…
Cicero recalls a passage of one of Gaius’s speeches: ‘Quo me miser conferam? quo vertam? in Capitoliumne? at fratris sanguine madet. an domum? matremne ut miseram lamentantem videam et abiectam?’  Cicero’s theme is the importance of actio, and he tells us that Gaius’s eyes, voice and gestures when uttering these words were such that even his enemies could not refrain from tears…
On the other hand Cicero could give Gaius lessons in rhythm. Take that sentence, he says, From Gracchus: ‘Abesse non potest quin eiusdem hominis sit probos improbare qui improbos probet.’ How much better if he had written ‘qui improbos probet probos improbare.’ (pp 43-44)
The stoics believed in speaking the truth in plain words; they eschewed ornament and emotional appeal. Their style, says Cicero, was a meagre one, hardly calculated to win popular applause. How true this was shown by the experience of Rutilius Rufus. As a good Stoic he expressed the strongest condemnation of such theatrical tricks as had won Galba acquittal, and when he was himself accused, quite unjustly, of maladministration, he disdained to use such arts. He made no appeals to the mercy of the jury and would not allow more than the simple truth to be said in his defence. ‘There were no groans or exclamations on the part of his advocates’ says Cicero, ‘no expression of grief or indignation, no appeals to the commonwealth, no supplication; why no one stamped his foot, for fear, I suppose, that the Stoics might hear of it.’ (p 45)
Wit as a weapon of oratory belongs to the Roman tradition. So no doubt does pathos. ‘Demosthenes’, wrote Swift, ‘who had to deal with a people of much more Politeness, Learning and Wit, laid the greater weight of his oratory upon the Strength of his Arguments offered to their Understanding and Reason. Whereas Tully [i.e. Cicero] considered the Disposition of a sincere more ignorant and less mercurial Nation by dwelling almost entirely on the Pathetick Part.’ Whether this analysis of national character is correct or not, the pathetic is a note which sounds stronger in Roman than in Greek oratory. It sounded at full blast in Antonius’ defence of Aquilius, when he contrasted the former glories of the consul and triumphant commander with his present piteous and precarious condition, displayed his client in person, sorrowing and dressed in mourning, tore open his shirt and showed his wounds. (pp 47-48)
 De Oratore I. 38, Brutus 103, De Hauspicum Responsis 41. In early life Cicero was more favourably disposed to the politics of the Gracchi. In De Inventione (I.5) they are bracketed with Cato, Laelius and Africanus as men in whom was ‘summa virtus et summa virtute amplificata auctoritas et quae et his rebus ornamento et rei publicae praesidio esset eloquentia.’
 De Oratore III .214, fragment 58 Malcovati, Oratorum Romanorum Fragmenta Liberae Rei Publicae. Cf. Quintilian XI. iii. 115
 Cicero, Orator 233
 Cicero Brutus (id) 114
 Cicero De Oratore I. 228
 De Oratore 237-230 Brutus 115. One of his advocates was Q. Mucius Scaevola, also a Stoic, whose sober legal judgements proved ineffective against Crassus’s mockery in the causa Curiana. See p. 47.
 De Oratore I 230. Other Stoic orators were Q. Aelius Tubero, whose mode of speaking, according to Cicero, matched the harshness and uncouthness of his life (Brutus 117, De Officiis III. 63), Mummius (Brutus 94, cf De Republica V. 11) and Fannius (Brutus 101).
 A letter to a Young Gentleman lately enter’d into Holy Orders.
 Cicero De Oratore II. 195.