I’m not trying to be difficult, but don’t understand why you aren’t using the numbers straight from Rasmussen:
http://www.rasmussenreports.com/public_content/politics/elections/election_2010/election_2010_senate_elections/final_rasmussen_poll_results_2010_senate_elections
For instance, this link says the final poll had Rossi up 1, while the actual is Murray by 3. That’s overestimating the Republican by 4, and you say they are “almost exact”.
This link says the final poll had Blumenthal up 7, the actual was 11, also overestimating the Republican by 4, and you say “right on target”.
Polls using Rasmussen's methodology via subsidiary POR were sponsored by two organizations: Rasmussen Reports and FoxNews. I'm using a 3rd party source that includes both. Obviously Rasmussen Reports only includes those done for them.
For instance, this link says the final poll had Rossi up 1, while the actual is Murray by 3. That’s overestimating the Republican by 4, and you say they are “almost exact”.
The final poll with Rasmussen methodology was commissioned by FoxNews, and showed a 49-47 Murray lead. CNN shows an actual result of 51-49 with 97% reporting. I call that almost exact.
Now, polls will fluctuate within (and occasionally outside of) the margin of sampling error. POR polls since October showed the following margins for Murray (oldest to newest): -3, -1, +3, -1, +2, all of which are consistent with an extremely close race, as it proved to be. (Compare to CNN, the Washington Poll, and the Elway Poll, all of which showed margins for Murray of over 5%). While the final poll nailed the correct winner and margin, the poll from a few days previous for Rasmussen Reports showing Rossi 48-47 was perfectly consistent with the actual result and well within the margin of error.
This link says the final poll had Blumenthal up 7, the actual was 11, also overestimating the Republican by 4, and you say “right on target”.
53-46 is well within the margin of error of the actual result of 55-43 (91% reported). As such, the poll was correct, right winner, very close to the margin. POR polls since October (oldest to newest): +10, +11, +6, +5, +13, +7. All of these results are within the margin of error of the actual result. Additionally, indications from Connecticut are that Democrats exceeded their expected results.