It's certainly not impossible to make the steep climb from community college to a high ranking PhD program.  I started my undergrad at PCC, too, graduated from PSU, just finished my MA at University of Washington, and now I'm heading off the the University of Chicago for my PhD.  I found it easier to get into a strong PhD program after getting my MA.  I applied to high ranking PhD programs straight out of my BA, and only got into one (with no funding).  Getting the MA made me a much stronger candidate this time around.  If this is an option for you, I'd highly recommend it.