Would absolutely kill small businesses in this country - that's the primary reason why I'm against it.
The effect on larger corporations could be somewhat counter-intuitive, since they generally have the money to affect their own coercion tactics on workers who wish to unionize.
Depends on the small business. If they treat their employees like cogs in a machine, they will attempt to unionize. If they treat them with respect and decency, they won't. Giving them extra incentive to do the latter is a good thing in my opinion.
You assume that small businessmen are stupid. If they see the legislation pass, the first thing they will do is lay off all *non-essential* workers (before they can unionize or something like that), and recalculate the amount they can afford to spend on payrolls. Then, if they have to deal with unionization, they have the ability to. In other words, maybe better paying jobs, but quite fewer numbers of them.
It will also continue to push businesses and people into states with a weaker union presence. If the union presence follows, see step 1. I think illegals will naturally become a smaller part of the workforce in the future.
In other words, if there's no secret ballot, do you somehow think that only unions will be influencing workers concerning the card check?
Not to mention all this strengthens the mafia enormously, but that's to be expected.