Upvote:5
As Pieter said, he wasn't eligible as yet. Tribune was one of the lower rungs on the cursus honorum. He had to wait at least 15-20 years before trying to become consul. But there was more:
The tribune had unique powers that allowed him to do far more than any consul could. He had the power of veto and could legislate laws by himself even if the whole senate was against it, bypassing the senate.
That was something a consul could easily forget, namely making laws without approval of the senate. Later in history they did, but by then the republic was almost an empire. Military force trumps just about everything. In Cracchus time a consul could legislate, but only with enough support from the senate. He would have to create a compromise. I'm not too sure if the senate would accept such a compromise here. Too many senators had too much to loose.
Becoming a consul was not easy. Fairly few senators managed to get that far. I'm pretty certain both Cracchi could have managed it, but that was by no means certain.
And finally, most politicians then and now look for quick solutions that work right away. Not something that might - or might not - work in 20 years time. Both Chracchi brothers were young men, they wanted to solve a nasty problem at that very moment. Not somewhere far away in the future.
By the way, only the tribunes of the plebs had the power of veto. Nobody else, including the consuls. The Cracchi wouldn't worry about a vetoing consul, that wasn't possible. But a consul buying one or more tribunes to veto for him was a very real possibility.
Upvote:10
According to the Cursus Honorum, Tiberius was not eligible to be Consul until the age of 42. As he was killed at the age of only 30 (163/2 BC to 133 BC) he was a long cry from being eligible for the Consulship, even given the extreme bending of the rules that was becoming commonplace about this time.
The Cursus Honorum was a succession of offices to be held by Consulship candidates, each one with a successively greater minimum age much as the minimum age to be a US Senator is 30. The minimum age to be a Praetor, the immediate prerequisite for the consulship, was 39, and was to be followed by a two-year term in the provinces as Propraetor before returning to Rome eligible to stand for the consulship.
As great an honour as it was to even become Consul, those who like Cicero made it in their year were even more esteemed, as never having lost an election and stood for every office of the course at the earliest possible age.