Participants in the bipartisan Senate filibuster talks remain optimistic they can make a deal that will head off a Republican decision to exercise the nuclear/constitutional/Byrd option.

One change that has occurred is Democrats are no longer demanding the right to filibuster future nominees whom they deem “extreme.”

Republicans note that Democrats have referred to virtually every Bush nominee to whom they object as “extreme,” meaning that including the word in any agreement would give Democrats a blank check to filibuster nominees in the future. Now, both sides are using the phrase “extraordinary circumstances,” which is believed would indicate a Democratic commitment to refrain from filibusters.

There has also been discussion of parity of demands. So far, Democrats have offered to refrain from filibusters — except in those “extraordinary” circumstances — in return for a Republican guarantee not to use the nuclear/constitutional/Byrd option for the remainder of the 109th Congress. Republicans, on the other hand, have discussed offering to refrain from using the option except in “extraordinary circumstances” — in other words, agreeing to the same conditions as Democrats. It is not clear whether Democrats will accept that condition.

But it does appear that Democrats are backing down somewhat on the number of nominees they would insist on killing as part of any agreement.

One scenario has Democrats agreeing to up-or-down votes for all nominees except William Myers and Henry Saad, meaning five currently blocked nominees would receive up-or-down votes in the full Senate.

Finally, as of now, Republicans plan to hold a cloture vote on the nomination of Priscilla Owen next Tuesday night. If no agreement is reached by then, Republicans will test the Democrats’ commitment to filibuster Owen.

If Democrats choose to continue, then the GOP plan calls for the vote that will end the filibusters.