The California grocery workers' strike began on October 11th, 2003, and continues to this day. Most people didn't expect Kroger, Safeway, and Albertsons to hold out this long, but after 103 days it's the striking workers who are looking weak (I know, I know, two LA Times articles in one day... blame Rough & Tumble).
It's interesting to consider the so-called "right to strike", and here's an article (from 1990) by Charles W. Baird that discusses some of the moral and legal issues. I wouldn't be surprised if the National Labor Relations Act has been modified since this article was written, but Dr. Baird's moral arguments are still persuasive.
The only job-related right that can be held and exercised by all people in the same way is the right to make job-related offers to others. Sellers of labor services have a right to offer to work for any employer on any terms the sellers wish. They do not have a right to compel any employer to accept such offers. In exactly the same way, employers have a right to offer to employ any worker on any terms whatsoever. They do not have the right to compel any employee to accept such offers. In short, the employment relationship is a contractual relationship based on mutual consent. In the absence of a contractual agreement to the contrary, no employee has a property right to any job.To summarize, any worker or group of workers has the right to bargain with employers for mutually satisfactory compensation; however, no one has the right to infringe on the contract rights of others by indimidating workers, employers, or customers, and no one is entitled to special protection above and beyond the value of the service they themselves are providing. That means that if an employer wants to fire strikers, he should be able to do so. Workers shouldn't strike if they think they'll be easy to replace; ease-of-replacement demonstrates that the workers are being paid at least fair wages, and possibly better. On the flip side, employers won't fire workers whom they are paying below-market wages; they'll have an incentive to get the employees back to work at slightly higher pay.
What about the right to strike? In the absence of a contractual agreement to the contrary, any employee has a right to withhold his labor services from an employer if he doesn't like the pay and benefits the employer offers. If each individual has this right, then a group of like-minded individuals can exercise this right together. In other words, all individuals who want to may withhold their labor services at the same time. If this concerted action induces the employer to acquiesce to the workers' terms, so be it. That will depend on the relative bargaining power of the two sides, and neither side has a natural right to any bargaining power advantage. Each side's bargaining power depends on the attractiveness of its alternatives.
However, and this is the central point, notwithstanding Section 13 of the National Labor Relations Act, like-minded workers who simultaneously withhold their labor services have no legitimate right to interfere in any way with the right of the struck employer to engage in voluntary exchanges with customers, suppliers, and other workers. Workers who are willing to work for a struck employer who wishes to hire them have a legitimate right to do so. Moreover, they may agree to accept the very terms of employment that the strikers consider to be unacceptable. Replacement workers have the same job-related natural rights as striking workers.
If the only thing protecting your job is a law prohibiting your employer from firing you, you're overpaid.