Sir James is visiting the Cadwalladers' house, complaining about Mr. Brooke's going into politics as a Whig.
Remember, Sir James has married Celia, Mr. Brooke's niece, so he has a family interest in keeping Mr. Brooke from making a fool of himself.
Context Time: most old, wealthy families, like the Brookes or the Chettams, were conservative Tories. They had an obvious interest in maintaining the status quo – after all, the status quo meant that they got to continue being rich and powerful.
The Whigs wanted gradual change, and the Radicals wanted, well, radical change.
So the fact that Brooke has bought the liberal newspaper is just adding insult to injury.
Mr. Cadwallader and Mr. Farebrother say that Brooke isn't just publishing the liberal newspaper now; he's actually thinking about running for Parliament as a Whig.
But they don't think he stands much of a chance against Bagster, the other Whig candidate.
Bulstrode, though, is campaigning for Brooke, and Bulstrode's opinions carry a lot of weight in Middlemarch.
Sir James then brings up "young Ladislaw," Casaubon's relative and Brooke's newspaper editor.
Mrs. Cadwallader calls him a "troublesome sprig."
Sir James doesn't want Brooke to run for Parliament for all kinds of reasons – Brooke is a bad landlord, and the opposition newspaper, called the Trumpet, has already started dredging up bad stories about the state of the cottages on Brooke's property.
Brooke walks in just then, and Mrs. Cadwallader points out the article in the Trumpet that criticizes Brooke's estate management.
Sir James hints that Brooke should consider putting in new gates on his estate, at least, and suggests that he hire Caleb Garth to do the job.
Brooke dismisses the idea as too expensive, and Mrs. Cadwallader points out that running for Parliament will be even more expensive.
But Brooke dismisses that, too, and then leaves in a hurry to avoid more criticisms from his friends.