4 ideas
Melmotte's wealth exists only as long as others believe in it; his power comes from the shared assumption that he is rich, not from verified holdings. Because every investor and aristocrat relies on everyone else's apparent confidence, no one checks the foundations, and the whole edifice collapses as soon as belief falters.
The South Central Pacific and Mexican Railway is promoted in London with almost no intention of building a line. Its board members profit by trading shares whose value rests on rumor and Melmotte's name.
Trollope argues that aristocrats who privately despise Melmotte still dine with him, court his heiress daughter, and back his parliamentary candidacy because his money serves their needs. By trading their status for his cash, the elite give the fraudster the legitimacy he needs, which makes them accomplices rather than dupes.
Dishonesty in the novel is not confined to one villain. It runs through marriage, where heiresses are hunted for their money, and through publishing, where literary reviews are traded as favors. It also shows up in gambling clubs that run on unpaid IOUs. Each small accepted deceit makes the next one normal, so Melmotte's large-scale fraud is simply the most visible outgrowth of dishonesty that is already everywhere.