To pass the cloture vote, it's not just about getting the requisite number of Republicans. There is a significant set of Democratic senators who will need to be persuaded.

Three centrists whose razor-thin election victories in November tipped control of the Senate to the Democrats now hold potentially decisive swing votes on the immigration measure the chamber will try to revive later this week.

All three Democratic freshman senators - Jim Webb (Va.), Jon Tester (Mont.) and Claire McCaskill (Mo.) - voted against efforts by Senate Majority Leader Harry Reid (D-Nev.) to shut down debate over the measure earlier this month. The freshmen each have controversial amendments in the package that will be considered once the Senate moves to resume debate later this week. And no member is decided on how he or she will vote on the underlying bill.

I was particularly surprised by the stance of Claire McCaskill, who was recently elected back in November as well, on most issues she seemed to be a standard liberal Democrat. But on immigration, she's pretty tough.

I've given up on the accuracy of polls after the kerfuffles of 2000 and 2004. I think the advent of caller ID, cell phones and the new media have rendered accurate polling obsolete.

That said, some polls seem to have been more accurate than others such as Quinnipiac and Rasmussen. Zogby is wrong so often that his polling doesn't figure in anymore.

Based on the latest polling data and from what I've read of the elections, I see the five most competitve Senate races playing out this way (incumbent listed first):

Santorum-Casey

Santorum is down in just about every poll. The RCP composite has him 13% down to Casey in a state where Democrats have a strong advantage in the two big cities. Santorum has been a lightning rod for liberals and it ust may have worked. I have Casey winning this by 4% unless Santorum can get the suburban Philly in Montgomery and Bucks Counties to turn out in large numbers.

In a response to this blogger's query, Missouri Senate hopeful Claire McCaskill rebuts Rush Limbaugh and his slander of Michael J. Fox.

"When people are confronted with something that's powerful and real and it's not what they agree with, they sometimes unfortunately attack the messenger. Sadly, that's what happened here. Only in politics would someone have the nerve to belittle someone that way. Mr. Fox deserves better respect than that." McCaskill says.

As for the Missouri ballot measure in question -- and the claim by rightwing religious zealots that the issue is NOT about stem cell research for diseases like Parkinson's (that afflicts Fox) but is a stealth cloning bill -- the National Institutes of Health supports the science:

With Risk of Cancer, Human Embryonic Stem Cells (hESCs) Can Improve Motor Function in Rat Model of Parkinson's Disease

Successful treatment for individuals with Parkinson's disease will be achieved when scientists can adequately replace the human dopamine-producing nerve cells (dopaminergic neurons) lost in PD. In 2004, NIH-supported scientists were able to successfully derive dopaminergic nerve cells from hESCs listed on the NIH Stem Cell Registry.

McCaskill says that is the point of stem cell research, as supported by her.

Right wing zealot and radio talk show hack Rush Limbaugh has accused actor Michael J. Fox of "acting" or being "off his meds" in a nationally televised ad, for the purpose of sensationalizing his Parkinson's disease. The campaign spot is in support of Missouri Senate candidate Claire McCaskill's support for legislation to garner funding for stem cell research.

Fox was in Chicago Tuesday to support House candidate Tammy Duckworth. In their report on the actor's local appearance, CBS2chicago.com interviewed neurologist Dr. Thomas Kelly. He says Limbaugh doesn't have his facts straight:

Fox's disease has progressed where he no longer only gets tremors, which can be controlled with medication, but has more erratic movements which are caused directly by his medicine.

"Chaotic, maybe writhing, dance-like movements, or dyskinesia, the movements I've seen in Mr. Fox, are due to his medications," said Dr. Kelly.

Today, I saw the ad by Michael J. Fox supporting stem cell research and Democrat Claire McCaskill. As he constantly rocked from one side of the screen to the other, you had to feel bad for him. His message was brief. "They say that all politics is local but how you vote could make a difference to me." He pointed out that he supports stem cell research. He pointed out that Jim Talent tried to criminalize it.

Recent polls are showing that Talent has moved ahead of McCaskill in the race for the Missouri Senate seat. This message could be just the thing to give McCaskill a win. It is pretty hard not to sympathize with Fox.

Regardless of party affiliation, health has to be the most important thing.

Watch the ad -- what do you think of it?

As a resident of California, where our Senate race is a gimme (Democrat Feinstein), it's been fun to follow the other key races as an outsider who can't affect the outcome. One of the more interesting sources I have found is The Fix by Chris Cillizza.

Every Friday he blogs for the Washington Post and addresses all sorts of politically relevant issues. This week he wrote about key House races, but last week it was the key Senate Races. According to The Fix, those races (as of a week ago), show the Senate landscape shifting towards the Democrats. His analysis is as follows:

• Washington - Republican Mike McGavick's "free-fall" following his mishandling of a past drunk driving arrest had ended, but the damage was done. Two recent polls showed Democrat Maria Cantwell leading McGavick by 9 and 10 points.
• Maryland - Republican Michael Steele continued to impress with his unorthodox ad campaign, but his central problem is his stance as a long-time supporter of George W. Bush. Polling showed the democratic candidate, Ben Cardin, with a mid single digit lead. Steele's chances hinge on an improvement in the national political climate, a change seen as increasingly unlikely.
• Virginia - A new Mason-Dixon poll showed Republican George Allen and Democrat James Webb tied at 43 percent -- a stunning reversal for Mr. Allen, who started the year running for president in 2008. A key to the outcome may be whether the Democrat Senatorial Campaign Committee or the National Republican Senatorial Committee weighs in with television ads between now and November 7th.