Obama raised the idea of free community college at his State of the Union speech earlier this year. It was popular among some circles, with Jonathon Alter even going so far as to call it the modern G.I. Bill. Most of the naysaying on the idea are along the lines of (a) community colleges are not effective enough at assisting students to graduate, or (b) graduating from a community college is not a guarantee of subsequent employment.
While its well and good that people receive the training needed to find and hold jobs, there is a distinct problem here that everyone is ignoring: that these students only need to go to a community college because public high schools have failed them. It used to be that high school provided the necessary training and certification for most trades and crafts, be it mechanics, welding, agriculture, cooking, and so on, for those going into the trades; or, for those headed to college, a more advanced level of history, arts, literature, mathematics and science, necessary for the college environment. But the middle school became the remediation for poor elementary school teaching; high school became remedial middle-school; and vocational/technical programs were cut in favor of "college prep" courses. Except, the "college prep" courses really aren't, and much of the first year or two of college is remedial education for the things you should have learned in high school, but didn't.
Essentially, the proposal for free community college is a concession that the public education system is broken and can't be fixed. I don't know what the best solution is, but it is no solution to just continue flushing money down the toilet of public education. Our education system began to go haywire in the 1960's and 1970's, so looking at ways of correcting the problem begins with identifying what changes to teaching and teaching methods began back then, and then removing those changes. It probably doesn't help that schools have increasingly become day-care centers as the traditional family has gone extinct.