How we cite our quotes: (Sentence)
Quote #1
We now administer the affairs of a nation in which the extraordinary growth of population has been outstripped by the growth of wealth in complex interests. (4)
Right up front, Roosevelt addresses the elephant in the room: there's not enough money for everyone, and the huge boom of money is tied up in "complex interests": aka businesses and Wall Street.
Quote #2
If, on the other hand, it turns into a mere crusade of appetite against appetite, of a contest between the brutal greed of the "have nots" and the brutal greed of the "haves," then it has no significance for good, but only for evil. (57)
Teddy's equating the greed of the wealthy to the greed of the poor, which is kind of apples and oranges. Wanting enough money to buy a new vacation home is not the same kind of want as wanting enough money to actually have a home.
Quote #3
If it seeks to establish a line of cleavage, not along the line which divides good men from bad, but along that other line, running at right angles thereto, which divides those who are well off from those who are less well off, then it will be fraught with immeasurable harm to the body politic. (58)
Roosevelt thinks that there can and should be a cross-class alliance, where people on both sides can agree on what's best for the country. It's kind of a utopic thought.