What Does "End of the Line" Mean?

GW and Ted Kennedy make mention of illegals going to the "end of the line" as if the illegals are not getting preferential treatment. Some would-be immigrants do start out as visa holders and live for a time in the U.S. before applying for and getting citizenship but it is not the general procedure for applying for citizenship. Normally foreigners who want to be citizens apply in their own countries and live there until the papers go through; if they go through.
Illegals on the other hand appear to be getting preferential treatment by residing here and getting an almost certain track to citizenship by living here illegally for a long period of time without being caught.
Another point--some have stated illegals only break one law; that of entering this country without documentation. What about document fraud, buying bogus green cards, or social security cards? Then there is falsely giving social security numbers to employers which is fraud. Some employers pay under the table to avoid paying taxes and the illegals avoid paying taxes as well. I'm sure there are other laws being broken as well so there appears to be a whole slew of laws being broken by illegals and others. The whole system corrupts our way of life, we are an immoral society because of it.