A day before presidential hopeful Mitt Romney took his "save Social Security" pledge to retirees in Florida, California labor experts floated a disturbing report.

One of the biggest implications for a massive crisis—and a possible focal point for overhaul—is in California, where a new study finds nearly half of workers who retire at age 65 will be at or near poverty level (i.e. $22,322 per year).

Authors of the study, which was released Monday by Berkeley's Center for Labor Research and Education, blame the shortfall on a few factors:

• Social Security overwhelmingly serves as the retirement income foundation for most California retirees, with employer-sponsored retirement plans far behind as their second income source. Social Security provides 79.1 percent of income for the bottom 25 percent of retirees by income, and 70.3 percent for the middle 50 percent.
• Employer-sponsored pensions provide the next largest source of retirement income, at 15.5 percent, for the middle 50 percent of workers.
• Only 52 percent of California workers work for companies that offer a retirement plan, compared to 58 percent for the United States as a whole. Of those who participate in an employer-sponsored retirement plan in California, 61 percent are in a defined-contribution plan such as a 401(k).

"Our research shows how important Social Security is to the middle class," says Nari Rhee of the UC Berkeley Center for Labor Research and Education, "And in order for today's workers to retire in dignity, they also need access to a supplemental plan that can provide secure income in retirement"