It adds emphasis to that phrase, and implies a deeper meaning
I think one about the significant issues that Japan confronts these days is not overpopulation. The Japanese populace has been declining over the previous decade or somewhere in the vicinity. The issue is not the quantity of individuals but rather the make-up of that populace.
The rate of Japanese individuals resigning or drawing near to retirement age has been expanding for quite a long time. Nowadays, there are more "old" individuals in Japan than there are "youthful" individuals. Japanese ladies are holding up longer to get hitched and couples simply are having the same number of youngsters as they did decades before.
This has put a tremendous strain on the Social Welfare framework on the grounds that there are essentially insufficient Japanese youngsters paying annuity premiums, charges or whatever to take care of the wellbeing expense and benefits advantages of every one of the individuals who either as of now have or will in the blink of an eye be resigning.
The answer is: Political bosses expanded their power by helping immigrants in return for their loyalty.
At that time, many of the political bosses realized that if they somehow can help the immigrants obtain their citizenship, the immigrants will become much more likely to return their favor.
This mean that they can influence the immigrants to vote for them during the election in exchange for the citizenship. This help the political bosses expanded their power.