As the prospect of reaching a filibuster-proof majority continues to dangle in front of Senate Democrats, Senators and aides warn that having 60 votes would not represent a panacea for their agenda — and that Democrats may better enforce party unity with a slightly smaller number.

“Having 60 is not a filibuster-proof majority,” one senior Senate Democratic aide said. “There is a presumption out there in the world that simply by having a certain number of Members that all of those Members will blindly vote a certain way. Anyone who watches the Senate knows that’s not true.”

With a late-breaking win in Alaska this week, Senate Democrats now have secured 58 seats, but a recount in Minnesota and a runoff in Georgia could expand that by one or two. Sixty votes are needed to beat back a filibuster in the Senate.

Senators said that whether Democrats have 58, 59 or 60 seats, the emphasis will be on party unity in order to push President-elect Barack Obama’s ambitious “change” agenda.

“I think there is a good understanding that, while we enjoy the privilege that the American people have given us to have a healthy majority, it’s still going to be a majority that may fall short of the 60, and therefore we’ll need as much unity as possible to move the president-elect’s agenda,” Sen. Bob Menendez (D-N.J.) said.

Senate Majority Whip Dick Durbin (Ill.) said the party’s Tuesday meeting on whether to rebuke Sen. Joe Lieberman’s (ID-Conn.) decision to criticize Obama and back Republican presidential nominee Sen. John McCain (Ariz.) also served another purpose.

“The caucus discussion yesterday on the future of Sen. Lieberman was also about reminding people that we are very close to breaking through the record number of filibusters [from this Congress], and I don’t think that was lost on anyone,” Durbin said.

Democratic aides did acknowledge that having 58, 59 or 60 will make it much easier than in the past to pick off Republicans, particularly given the apparent mandate that voters gave Democrats on Nov. 4. In the 110th Congress, Democrats operated with a narrow 51-49 majority.

Still, another senior Senate Democratic aide said it might be easier for Majority Leader Harry Reid (D-Nev.) to call for party unity if he is just shy of 60 votes. Even with 58 seats, “60 is within striking distance on most bills, and it doesn’t raise false expectations that we can do anything we want,” the aide said.

Of course, Democrats say privately that they believe they may have hit their limit at 58. The runoff in Georgia between Sen. Saxby Chambliss (R) and Democrat Jim Martin remains a long shot for them, and Sen. Norm Coleman (R-Minn.) is holding a slim lead over the Democratic candidate, comedian Al Franken, as that race heads into a recount filled with legal wrangling.

Either way, Reid has indicated that he plans to govern from a pragmatic center.

“It’s not in Sen. Reid’s nature to steamroll people, so regardless of the size of his majority, he will work to reach out to Republicans,” Reid spokesman Rodell Mollineau said.

Reid is also facing the reality that many of his new Members are from more conservative Western states, and that existing splits in the Democratic caucus over a wide variety of policy issues are likely to continue to bedevil him in the 111th Congress.

Having lost seven seats so far, Republicans also are stressing party unity.

Chief Deputy Minority Whip John Thune (R-S.D.) said Republicans have already begun to talk about the need to stick together and protect each other’s rights.

“The leader has been making that point, and most members of the rank and file understand that as well because when you get down to these numbers, if you want to have an amendment considered, obviously we’re going to have to hang together to make sure that the majority doesn’t run over us,” Thune said.

He added, “Whether we’re going to be able to accomplish that remains to be seen, but certainly that mindset is taking hold.”

One senior Senate GOP aide added that Democrats will clearly have an easier time picking off Republican moderates, but said the message to those moderates and others is that by cutting your own deal, you could be denying nearly 40 of your colleagues a voice in the process.

“Whether we have 41 or 42, [Democrats are] going to win some battles,” the aide said. “But Republicans believe that if we stick together, we can win some of the wars.”

Practically, Democrats face other obstacles when faced with either a 60-Member majority or even 58. Already, Reid has made it known that he will begin enforcing a little-known Senate rule that limits the number of subcommittee gavels that full committee chairmen may wield.

“Sen. Reid is committed to ensuring that we maximize the full potential in our caucus,” Mollineau said. “We have some great leaders in our caucus. They are motivated and have great ideas, and Sen. Reid is committed to giving them a platform to help deliver the change we promised.”

The process is likely to be slow-moving, however, aides warned. Reid will have to go down the list of Senate seniority to find out which subcommittee panels chairmen will relinquish, and because there are more subcommittees than there are members of the Democratic caucus, some chairmen may be allowed to continue to preside over more than one subcommittee.

Both parties have postponed announcing their committee leadership and membership. That process has not begun this year because of the two undecided Senate races, aides in both parties said.

Once those elections have been resolved, however, Reid and Senate Minority Leader Mitch McConnell (R-Ky.) will likely sit down to discuss the size of committees and how big of a majority Democrats should have on panels. Currently, Democrats have a one-seat advantage, and historically, parties that reach 55 Members get a two-seat majority.

Democrats would have a powerful case to make about having a three-seat advantage if they actually reach 60 votes, because it would likely be nearly impossible for Republicans to filibuster the organizing resolution under such a scenario. But without a 60-vote Democratic majority, Republicans will be key to any agreement.