Here are screen shots of a couple of recent examples.
It would seem the Daily Kos polls are very kind to Democrats.
Here is some of what Markos had to say about his pollster.
From Daily Kos:
We contracted with Research 2000 to conduct polling and to provide us with the results of their surveys. Based on the report of the statisticians, it's clear that we did not get what we paid for. We were defrauded by Research 2000, and while we don't know if some or all of the data was fabricated or manipulated beyond recognition, we know we can't trust it. Meanwhile, Research 2000 has refused to offer any explanation. Early in this process, I asked for and they offered to provide us with their raw data for independent analysis — which could potentially exculpate them....