Putting news of President Obama's approval rate dipping below 50% for the first time in historical perspective, USA Today runs an excellent interactive chart plotting presidential approval rates since 1945.

When comparing various presidents to each other, as of right now, President Obama most closely tracks Ronald Reagan.

With Sen. Ben Nelson (D-NE) announcing today that he would vote on Saturday night to bring the health care reform bill up for debate, attention turns to four others whose votes may indicate the ultimate success or failure of the bill.

• Sen. Blanche Lincoln (D-AR) -- According to Politico, she's already told Reid how she'll vote but she hasn't made her intentions public yet. A new poll shows her vote may be critical to her re-election prospects next year.
• Sen. Mary Landrieu (D-LA) -- She's voiced opposition to the public option, but Bloomberg notes there was a $100 million addition to the bill to win her support
• Sen. Joe Lieberman (I-CT) -- We've already documented his threats to block the public option, but he's stated publicly he'll at least vote to bring the bill to the Senate floor.
• Sen. Olympia Snowe (R-ME) -- She was the only Republican senator to vote the bill out of the Senate Finance Committee, but she's also voiced opposition to the public option.

The Saturday vote is mostly political theater at this point -- even reluctant Democrats know they must at least bring the bill to the floor for debate -- but it's not clear how each of the four will actually vote.

The Senate Ethics Committee publicly admonished Sen. Roland Burris (D-IL) for "discrediting himself and the Senate in the way he sought appointment to the seat of now-President Barack Obama," Roll Call reports.

In a public letter of qualified admonition, the committee found that Burris "should have known that you were providing incorrect, inconsistent, misleading or incomplete information to the public, the Senate and those conducting legitimate inquiries into your appointment to the Senate."

There's an online version of the Inside Tim Russert's Office exhibit that opens today at the Newseum.

Earlier this month we noted that Gallup's daily tracking poll showed President Obama's approval rate bouncing around 50% for several months but never actually breaking through that line.

Apparently that streak will end today when Gallup updates its numbers at 1 p.m. ET.

Who wants to bet that Rush Limbaugh takes credit on his radio show today?

DCCC chair Chris Van Hollen (D-MD) tells The Hotline that the key to Democratic fortunes in the midterm elections will be mobilizing the voters who showed up for last year's presidential election.

Said Van Hollen: "If you were to see the kind of turnout in the Congressional elections of 2010 that you saw in these off-year elections in Virginia and New Jersey, that would spell trouble. But there's no reason to believe that we're going to have that kind of turnout, because voters who came out to support Obama will understand that ... he has a huge stake."

A new Marist Poll in New York finds Andrew Cuomo (D) has massive leads over both Gov. David Paterson (D) for his party's gubernatorial nomination, 72% to 21%, and against Rick Lazio (R) in the general election, 69% to 24%.

Said pollster Lee Miringoff: "Right now, Andrew Cuomo has a clear path to become governor. If he could fast-forward to next November, I'm sure he would."

A new Rasmussen survey finds 51% of Americans believe canceling the rest of the economic stimulus money would create more jobs than actually spending it.

Derek Thompson: "That is insane... The idea that canceling the stimulus would create more jobs implies that passing the stimulus has actually killed more jobs than it's created, which is bonkers. Let's say you don't want to consider infrastructure spending or green technology spending or a single job that might have been created in the private sector. If nothing else, the tens of billions we've sent to state budgets have, without question, saved hundreds of thousands of jobs, like teachers, that are supported by state taxes. It's just a very basic fact."

"We'll find out when the votes are taken."

-- Senate Majority Leader Harry Reid (D-NV), quoted by The Hill, when asked if he has the 60 votes needed to bring his health care bill up for debate.

First Read: "Realistically, is more being made out of this drama than should be? Does it make political sense for any Democrat to prevent even debate on this bill even for Democrats who may eventually vote against it? To not allow debate would be a slap in the face of the Dem base and no Dem officeholder would do that, would they?"

Interesting observation by Ben Smith: "Ever since cooperating with a big New Yorker article, Richard Holbrooke's profile has been so low at home that he at one point gave an interview to a reporter to deny that he's lying low."

Holbrooke was once seen as the most powerful voice in shaping policy towards Afghanistan. Now, he's nearly invisible.