So yesterday we reported on a possible push poll being conducted in Oregon by a company called Western Wats. A caller told one Oregon woman we spoke to about tax increases being supported by Democratic Senate candidate Jeff Merkley, then asked whether the information made her less likely to support Merkley -- who's in a tight race with Republican incumbent Gordon Smith.

Western Wats had told us yesterday that its client was NMB Research, who did not return our call. But today, Stacey Jenkins of Western Wats called back to say that, after speaking again with their client, Western Wats had been authorized to tell us that the client is in fact Public Opinion Strategies (POS), a well-known GOP polling firm. POS, Jenkins said, had asked Western Wats yesterday to give us the name NMB Research as the client.

Jenkins could not answer why POS had directed Western Wats to give what appears to be misleading or incomplete information to a news organization.

A representative for POS did not immediately make available to TPMmuckraker anyone who could provide more information, or clarify the relationship between POS and NMB Research, but pledged to do so.

POS is a major GOP polling firm, founded by respected veteran pollsters Bill McInturff, Glen Bolger, and Neil Newhouse. Its involvement may indicate that the call was not part of a push poll, but rather an effort to test negative messages with a sample group of voters, for research purposes -- a possibility we suggested yesterday.

We'll keep you posted as we learn more.

Late Update: Public Opinion Strategies sent the following statement to TPMmuckraker this afternoon:

NMB Research is a separate legal entity with a separate office set up by the members of Public Opinion Strategies. It was established to comply with coordination rules of the Bipartisan Campaign Reform Act. NMB is retained by a number of clients involved in public policy research, issue advocacy, and independent expenditure campaigns. The establishment of NMB ensures compliance with the coordination rules of the Bipartisan Campaign Reform Act.

Neither Public Opinion Strategies nor NMB Research engages in push polling, voter ID, or GOTV programs.

We've contacted Neil Newhouse, a founder and senior pollster with the firm, to ask specifically about the Oregon call we reported on yesterday, and as always, will keep you posted.

Later Update: Neil Newhouse emails to say: "The poll was done by NMB and included more than 20 questions, including some message testing regarding Jeff Merkley."

He adds: "It was not a push poll, but a standard message-testing survey."

In other words, the call was designed to test which negative message about Merkley voting for tax increases would be most effective with Oregon voters.