The Heritage Foundation estimated that the bill would cost America $6.3 trillion over the lives of legalized illegals, but I knew that couldn’t be right. When you’ve got Chuck Schumer quarterbacking your legislation, you’re bound to end up in the black, right?

Yep, according to CBO. As Ace puts it, “Apparently the best way to close a budget deficit is to have lots and lots of poor people.”

The bill would increase spending by $262 billion between 2014 and 2023, but would increase revenue by $459 billion, according to the non-partisan office.

In the next decade, it would reduce the deficit by $700 billion, CBO said…

The CBO normally uses a conventional 10-year budget window and this has been a sore point for opponents of the Gang of Eight bill, who had called for a longer-range estimate.

The chief Senate critic of the immigration reform bill, Sen. Jeff Sessions (R-Ala.) last month said the bill will be costly once illegal immigrations qualify for entitlements.

Here’s the report, if you want to wonk out early before Phil Klein, Yuval Levin, Ramesh Ponnuru, and other conservative number-crunchers weigh in. The trends make perfect sense, though: As they join the labor force, young illegals will widen the tax base for entitlements like Medicare and Social Security. They’re paying in, but they’re not taking out yet — all the more so if the Gang of Eight bill ends up barring them early on from participating in programs like ObamaCare. This is what Jeb Bush was getting at last week when he chirped excitedly about immigrant families being more “fertile.” The more taxpayers you have soon, the more the entitlements crisis can be delayed. Emphasis: Delayed, not denied. Fast-forward 40 years, when taxpaying illegals start enrolling in Medicare, and what’s the solution then? Presumably, it’ll be … another amnesty, right?

As you might expect, noted fiscal conservatives Marco Rubio and Chuck Schumer are ecstatic. CBO scores may be near-worthless as predictive devices, but as political capital they’re very valuable. Remember how excited Democrats were when CBO initially scored ObamaCare as reducing the deficit by $140 billion between 2013 and 2019? A year later, CBO adjusted that downward to $95 billion. A year after that, they adjusted it downward again to … $4 billion. I’m sure nothing like that will happen here, though, especially after Democrats get to work on pressuring Republicans after the bill passes to make the benefits more generous or else be demagogued as anti-Latino:

Bill sponsor Sen. Chuck Schumer, D-N.Y., called the report “a huge momentum boost for immigration reform.”

The White House also lauded the CBO report, saying the numbers are “more proof that bipartisan commonsense immigration reform will be good for economic growth and deficit reduction.”

And Sen. Marco Rubio, a Florida Republican who has worked to woo conservative support for the bill, said in a statement that the report “further confirmed what most conservative economists have found: reforming our immigration system is a net benefit for our economy, American workers and taxpayers.”

Sure is. If the entitlement regime is unsustainable long-term now, and you’re suddenly adding a huge population that’s likely to vote on balance to preserve that regime and promote the Democrats who protect it, then in 40 years all of this will be a, er, “net benefit for our economy.” I wonder what the average annual rate of GDP growth needs to be between now and, say, 2050 to make Medicare and Social Security able to shoulder that extra load. Semi-serious question for Rubio: If immigrant-fueled economic growth is the solution to America’s deficit problems, then we should actually relax border security under the bill, right? Screen for dangerous people coming over the border, obviously, but if their record is clean, let ’em in and hand them a green card. We can’t be more than, say, 100-150 million illegals away from erasing the national debt, no?

By the way, as of last November, the federal deficit was growing at a rate of $6 billion per day. Even if you cut that in half via the extra revenue generated by legalization, the total savings from the Gang of Eight bill over the course of a decade would dig the feds out of a hole for roughly … 66 days.