Well, here's a shocker. This bill does nothing for small businesses. What's that you say? They lowered the corporate tax rate and put in pass through provisions to give an additional 20% deduction! Meh, not what it seems.
First, if you are a "small" business, as opposed to an llc or an s-corp with huge earnings and very low overhead, you don't get to use the new pass through provision.
Look, small businesses don't generate a lot of corporate profit. The money goes to expenses and salaries. Any money left over doesn't amount to much, and that is what gets the new lower corp tax rate.
But lets say you are a contractor, and get paid on a 1099. No matter what type of corp you run, the IRS will make you pay yourself a fair wage. You can't be a doctor and claim minimum wage on your corp tax returns. So more than likely, your salary is going to be at least 2/3 of your company revenues. Those w-2 earnings get taxed at as normal income.
The other 1/3 (minus business expenses) is taxed at the corporate rate. And at some point you will want that money, so you get it as a dividend. Dividends to you are taxed lower (I think 15% at fed level) but you are taxed by both feds and state. So now your company paid a corporate tax, and you pay a dividend income tax. It adds up to more than if you took it all as w2 salary.
The way this works is if your company has no employees (or just a small clerical staff) and high revenues; then everything is distributed immediately as a dividend with a big deduction. There is a provision to allow this case (the corker/hatch provision) at lower rates.
Large corporations do generate profits, and those are taxed at the new lower rate. But they can turn around and use that money to enrich investors - either through dividends to stock, stock buybacks, or bonuses to directors. Less corp tax means more money they can distribute to investors and directors.
Service providers (doctors/lawyers/accountants/consultants/etc) can't take the new pass through deduction. There are also income limits to prevent real "small" businesses from using it.
The benefits (surprise surprise) are targeted at large corporations, very wealthy wage earners, and very specific corporate structures, mostly used in real estate trusts.
This isn't going to help main street. Unless $5/month lower tax is going to make a difference to your life. But don't forget, health insurance will be much more expensive (even for corporate plan participants), and medicare/medicaid benefits will be lower, so someone will need to pay the difference or be denied services.