Sen. Marco Rubio, R-Fla., is pushing a letter from Social Security Chief Actuary Stephen Goss purporting to show that his immigration bill will bolster Social Security finances by $4.6 trillion. It does no such thing.

What the letter does say, is that the 1 million legal immigrants who come to this country under the current system will bolster Social Security finances by $4 trillion over the next 75 years. Adopting Rubio’s plan for increased immigration would only add about $600 billion to Social Security finances over the next 75 years. That is not nearly enough to cover the program’s current $8.6 trillion hole.

However, by granting citizenship (and therefore Social Security benefits) to illegal immigrants now, Rubio will make it much harder to reform Social Security in the near future.

Just look at how liberals are reacting to last week’s Social Security trustees report showing stronger revenues after the expiration of the payroll tax holiday. Here is Paul Krugman:

Start with Social Security. The retirement program’s trustees do foresee rising spending as the population ages, with total payments rising from 5.1 percent of G.D.P. now to 6.2 percent in 2035, at which point they stabilize. This means, by the way, that all the talk of Social Security going “bankrupt” is nonsense; even if nothing at all is done, the system will be able to pay most of its scheduled benefits as far as the eye can see.

If Rubio’s immigration plan passes, Social Security’s fantasy “trust fund” will be flooded with new revenues from amnestied immigrants and increased immigration. This will push back the depletion of the trust fund well past 2033. In other words, after amnesty, liberals will find it even easier to deny that the United States has an entitlement spending problem.

Worse, all of the amnestied immigrants will eventually make Social Security’s shortfall much worse when it finally does hit because there will be so many more Americans dependent on the system.

So amnesty actually does a double-whammy to conservative entitlement reform efforts. It makes the problem easier to deny now, thanks to increased revenues into the system, and it makes the crisis bigger later when all those extra retirees start draining the system.

Why Rubio is running around bragging about this is beyond me.