My answer was quick but I disagreed with her agreeing with Robin Seager that Cicero did not popularise the term ... I'd put my book about and thoughts regarding Marius on hold during my recovery, so hats off to Irene for getting me thinking about him again! This was my comment, which is worth sharing with those who don't read Irene's blog:
"Colleen McCullough may write novels, but they are remarkably well researched and she's clearly got a great brain and has given the various issues and ideas in them a lot of thought.
"I've been working on Marius, Cicero's slightly older cousin, who was The Big Man in Rome at the start of Cicero's career. Although many modern sources describe Marius as a Populares, I don't think he himself would have - partly as the concept of formal political parties was alien to his period, and mostly because the term was not used.
"So did Cicero coin the term? I think it's highly likely - or at the very least he popularised a term that came to be used in the post-Marius generation: after Sulla, in the days of Marius' nephew Julius Caesar.
"I think Seagar is wrong in that Crassus may well have used the term popularis, and may well have exploited the "notion of the sovereignty of the whole people" but ... so did Brutus the elder, so did Scipio Aemilianus, so did the Gracchi, so did Marius ... but harnessing the will of the people and having a more formal political party or movement are two different things ....
"Brilliant post Irene - it's been a while since I've felt able to think about these sorts of things, and this post really did make me think."