You've heard by now that long-time Sen. Repub moderate Arlen Specter is switching to the Dems. This is big, in several ways, and even bigger if coupled with the seating of Al Franken in the Senate in June. It may also have implications for the question of that happening. So, analyzing as fast as my aging fingers can go, having consulted two of the sharpest Minnesota-based analysts of matters congressional (Kathryn Pearson of the U of M and Steve Smith of Washington University) here goes:

Specter's full statement: Lays out his reasons: As the Repubs have moved to the right, he feels his views align more with the Dems now. He will run for a sixth Senate term in 2010 in the Dem primary. Many Pennyslvania Repubs had turned against him because of his moderate views and he was trailing in polls against a conservative Repub for the 2010 Repub primary. Says the statement, with impressive candor: "I am unwilling to have my twenty-nine year Senate record judged by the Pennsylvania Republican primary electorate."

Smith said he doesn't expect Specter to move very far left. In his statement, Specter said he would not become an automatic vote for the Dems on every issue. But Pearson said that since he plans to seek the Dem nomination and may face challengers more liberal than himself, he will have to show the Dem primary electorate that he is one of them. That may mean voting the Dem line more than he ever could have as a Repub. She says this may happen on "a lot of votes that are below the radar," especially on issues where Specter had not previously taken a big, clear position. But it will happen.

(Specter specified in his statement that he is not switching his opposition to the pro-labor position on the Employee Free Choice Act (EFCA), so the Dems may still, even with Franken, be one short on that issue.)

The Tuesday lunch: The Senators lunch with their party caucuses on Tuesday. Specter said he will not attend either lunch today. But you can bet that by next Tuesday, he will be greeted with open arms by the Dems.

59-40. That's the new partisan makeup of the Senate, with the Minnesota seat still unfilled. It means that a filibuster can still succeed if the Repubs hold their ranks. For the short term, pending the Minnesota outcome, it increases the leverage of the two Maine Repubs, Sens. Olympia Snowe and Susan Collins, who would be the likeliest candidates for the 60th vote needed to pass Dem bills.

But it's a mistake to assume all 59 Dem votes on every issue. Pearson noted that there will be issues on which the Dems' big challenge will be to hold their most conservative members, such as Nebraska Dem Sen. Ben Nelson and now, perhaps, Specter. On fiscal restraint issues, North Dakota Dem Sen. Kent Conrad may be an unreliable Dem vote. Indiana Dem Sen. Evan Bayh has, in recent years, broken party ranks more often than any other Dem Sen, but he hasn't been a player in the swing vote game so far this year.

If Franken gets seated: That makes 60 Dems, which means the Repubs can't stop a bill without some help from Dem defectors. Said Pearson: "This is huge. It means it will be that much easier for Obama to pass his major legislative priorities. This is very good news for the White House." President Obama has already called to embrace Specter and pledge full support.

What it does to Franken/Coleman: It intensifies the limelight on our race. Said Pearson: "Every national story about the Specter switch will have an Al Franken section. " Said Smith: "Everyone will portray the arrival of Franken as a pivotal moment, and him as a pivotal player." It increases the incentive for the Dems to get him in and for the Repubs to keep him out.

What it does for the Dems ability to get him in: Probably nothing, at least until the Minnesota Supreme Court rules, sometime in June. Dem Sen leader Harry Reid has committed not to do anything until that happens. If the Supremes rule for Franken, and if Gov. Pawlenty issues an election certificate, Franken probably gets seated very soon and probably would been seated under those circumstances without the Specter switch. But if all that happens and the Sen Repubs still try to block him (this is a long shot, but possible) they would have to hold all 40 of their members for a filibuster to prevent the seating of a certified winner. That's one fewer member than they had yesterday and means they would have no margin for error.

It may intensify the spotlight on Gov. Pawlenty: The Specter switch doesn't do much to help the Repubs keep Franken out (maybe motivate the base even more, maybe a new only-your-contributions-can-prevent-a-filibuster-proof-Dem-majority pitch in the fund-raising letters). But the most motivated Repubs will be trying to think of how they can stop Franken from getting that certificate, and they may decide that Tim Pawlenty is their best hope, at least for delay. Once the state court finishes the process of deciding who got the most votes, the governor must prepare and sign the certificate. But the law doesn't impose a deadline for him to do that.

Pawlenty has suggested that he may wait a while, study the ruling, see if any federal court might issue a stay, even do his own analysis of whether the ruling dealt properly with the issues. If he appears to have any discretion in the matter, Pawlenty may come under intense pressure from national Republicans to delay as long as possible. Given the growing impatience of the Minnesota public to get a second senator seated, he will also be under countervailing pressure to sign without delay.

If the MN Supremes include in their ruling an explicit order to the governor to issue the certificate, that will take Pawlenty off the hook. He has said that he will abide by court orders. But if they don't include a specific order, Pawlenty may have to decide whether he sees his future in Minnesota politics, or whether his presidential aspirations mean that he needs to prove himself to the national Republican base.

Said Smith: "The pressure on Pawlenty is gonna be tremendous." Said Pearson: "Until now, the public is blaming Coleman for delaying the outcome. If Pawlenty does anything to delay the outcome, he will face tremendous criticism from Minnesotans."

Smith had one technical prediction. Just before the Supreme Court rules, Coleman's legal team may file a fresh lawsuit in federal court based on its federal constitutional arguments. Most legal scholars agree that a separate federal action should not have any impact on the issuance of the state election certificate. But if such a case is filed, said Smith, Pawlenty could at least claim that he has to wait to see if the federal courts have a different view of the matter or whether a federal judge might issue a stay.