They are actually laid off, and collect unemployment for 2 years. "Fired" nowadays means the employee did something really bad (like criminal). Otherwise it is much easier to lay off, no lawsuits to worry about. Either way you still lose your job.
Pharmaceutial companies, defense contractors, auto companies, and all businesses closely match workforce against demand for their goods and services. Headcount is watched like a hawk.
These CEOs are simply saying their best guess is that the economy will not improve with Obama's reelection. Hence they will not hire new employees, and may have to lay off current employees. Again this is just a guess, and if business picks up, they will hire regardless of who is president.
The biggest issue on the table now is healthcare costs, no one in business (or government) has the slightest idea what they will be. The new healthcare law has over a thousand references that the Secretary of HHS "may", "shall", and "determines" whatever rule is under consideration at the moment. HHS can make healthcare cost as little or as much as they want, simply by rulemaking. Business cannot operate with that uncertainty, period.
Just imagine if the cost of insurance on your home or car could double or quadruple in a month. Would you buy a home or a car? Or put it off as long as you can? It does not matter if it is un-American or unprincipled. The money is just not there, period.
So take all these economic pronouncements with a grain of salt. No one can predict the future and no CEO is going to stand behind one of their promises if it hurts their business.