It ain't easy work to get up to q and z.

You have to give nearly all your time and attention to it.

Of course, you may have some business or occupation on the side, but the great business of your life must be politics if you want to succeed in it.
A few years ago Tammany tried to mix politics and business in equal quantities, by havin' two leaders for each district, a politician and a business man.

They wouldn't mix.

They were like oil and water.