They’re actually lowballing it, I think, by assuming only 45 safe Democratic votes right now. You’ll lose a couple of Dems on this, but nine? Mark Pryor already did his good deed to impress Arkansas conservatives by voting no on expanded background checks. Joe Manchin doesn’t have to face West Virginians again until 2018. Besides, immigration reform already polls well in general terms and today’s flashy Corker/Hoeven amendment gives fencesitters a way to support the bill while claiming that they held out until there was “real” border security included. Let’s assume that there are really more like 49 Democrats prepared to vote yes, plus the four Republican Gang of Eight-ers, plus Corker and Hoeven, plus the dependable RINOs like Kirk, Murkowski, and Collins. Kelly Ayotte’s already declared her support, and Orrin Hatch made a deal with Schumer during the Judiciary Committee mark-up on visas for high-skilled workers. That’s 60, even by a conservative estimate, and that’s enough to break a filibuster. With that kind of bipartisan political cover, expect a few more Dems to take the plunge — and multiple GOPers along with them.

For some reason, WaPo has Dems Mary Landrieu and Mark Begich as “likely” yeses and Collins as merely a “potential” yes. That seems backwards to me, notwithstanding Collins’s worries about being primaried by tea partiers. But no matter; they’re probably all on board in the end. More from the whip count:

POTENTIALLY YES (6)

Alexander (R-Tenn.)
Blunt (R-Mo.)
Chambliss (R-Ga.) – retiring
Collins (R-Maine)
Heller (R-Nev.)
Johanns (R-Neb.) – retiring

UNDETERMINED (19)

Burr (R-N.C.)
Chiesa (R-N.J.) – temporary appointee
Coats (R-Ind.)
Coburn (R-Okla.)
Fischer (R-Neb.)
Isakson (R-Ga.) – retiring
Johnson (R-Wis.)
McConnell (R-Ky.) – up for reelection in 2014
Moran (R-Kan.)
Portman (R-Ohio)
Thune (R-S.D.)
Toomey (R-Pa.)
Wicker (R-Miss.)
Baucus (D-Mont.) – retiring, voted against 2007 bill
Hagan (D-N.C.) – up for reeleection in 2014
Johnson (D-S.D.) – retiring
Manchin (D-W.Va.)
Rockefeller (D-W.Va.) – retiring, voted against 2007 bill
Tester (D-Mont.) – voted against 2007 bill

They forgot that Tom Coburn’s also pledged not to seek another term in 2016. Assuming that he’s retiring too, that leaves seven senators who have nothing to lose by voting yes, plus Christie’s appointee from New Jersey who’s all but a cinch to vote yes as well. That’s 68, with 17 still left on the fence to be gotten. Schumer’s said all along that he wants at least 70 votes for the bill in order to apply more pressure to the House. Think he, O, and Reid will be able to shake loose two more votes from those 17? Manchin’s there, as are bluish-staters Pat Toomey, Dean Heller, and Rob Portman. Jon Tester’s showed that he’s not afraid to be a loyal Democrat despite hailing from a red state by voting for expanded background checks and endorsing legalized gay marriage. Honestly wouldn’t surprise me if they ended up with something like 75 votes instead of 70.

Like I said this morning: This is all fine, and possibly even politically beneficial, if you think the House is prepared to resist the Senate pressure and drive a hard bargain. If not, we’ve got big problems. And by the way, if you’re feeling suddenly optimistic about border security because of the big surge in Border Patrol demanded by Corker/Hoeven, go have a look at the graph DrewM posted. The growth area in illegal immigration in the years to come, according to CBO, isn’t people crossing the border illegally and outrunning the BP. It’s people being admitted perfectly legally under a visa and then quietly disappearing once their visa expires. How does extra Border Patrol solve that problem? It doesn’t, but it makes for an awesome talking point when you’re trying to get 70-75 votes in the Senate.