(AP) -

An analysis by the Social Security Administration says a bipartisan immigration bill pending in the Senate would boost the retirement program's trust fund by adding millions of taxpayers to the economy.

The finding comes in a letter to Sen. Marco Rubio, R-Fla., who requested the analysis, from Stephen C. Gross, chief actuary for the agency.

It could provide a boost for the immigration bill, which has been attacked by some conservatives as overly costly, as the Senate Judiciary Committee prepares to begin amending the measure on Thursday.

The analysis says the bill would add more than $300 billion in net additional revenues to Social Security and Medicare over the coming decade.

Gross writes that the overall effect of the bill on the long-range trust fund balance "will be positive."

Does this change your thoughts on the immigration bill?  Or do you think it's a case of something looking good on paper, but in reality it won't work?