Yet more from M. Gelzer's Caesar....I think it presents irrefutable secondary source evidence of some of what was wrong with the oligarchic administration.
Just as his agrarian law showed a way out of Italy's social crisis, so he now attacked another cancarous growth in the oligarchic administration of empire, the gradual destruction of the provinces through the depredations of Roman governors. On one point all Romans were more or less agreed: the provinces existed to be exploited for the benefit of the Roman people. But under the prevailing system the goose that laid the golden eggs would not last forever. The members of the oligarchy regarded it as their prerogative to cover the enormously increased financial demands of political life with their takings as provincial governors. Strict control could prevent this activity from becoming intolerable, but mutual conivance happens to be the traditional weakness of oligarchy. Popular policies, which had emerged with the Gracchi, only worsened the situation with the one-sided favouritism shown to the knights---the public tax-farming companies and Roman finaciers sucked the blood from the provinces no less than the senators---and with the senseless increase in electoral expenditure, not to mention the fact that the senatorial representatives of this party behaved not a whit better in the provinces. There were, however, some honourable members of the nobility, from whose ranks there came in 149 the first law against the taking of money by magistrates, which provided for the trial of this offence before a special court. This was followed by two laws with stricter regulations, passed in the interests of the equestrian order. Next Sulla's law was effective until 59. Caesar now produced a careful and very comprehensive revision of the whole subject, the lex Iulia repetundarum, which remained in force from then on thoughout the whole Imperial period.
The law contained exact definitions of the offences and the classes of persons that came within its scope. In addition to the magistrates, the senatorial members of their staff, in particular their legati, were included; further also senatorial jurymen, plaintiffs and witnesses who took bribes. The law went on to lay down a new procedure for the conduct of trials and, in connection with its main theme, provided a mass of regulations for provincial administration. The lex Iulia contained nothing new in principle, but ti was drafted more precisely and strictly than its predecessors and so formed an excellent instrument for the supervision of the senatorial order. Seen from the standpoint of the empire as a whole, a lex reptundarum which ignored the knights was decidedly a half-measure, however much it demonstrated its author's mastery in the administrative field. Even at the time, it met with the approval of the experts---and of Cato---and, as far as we know, was adopted by the people without opposition.