That's what the Whig Party said. Actually, legal immigration will make the Dems the permanent majority party.
They are the recumbents in seats that are quite safe, for the most part because of various demographic factors. About 30% of America still comprises districts in which the Latino-Black-Single MOM-LGBT-Youth-Bureaucrap-Publicly Subsidized-SEIUMember-and other random freebiesucker coalitions amongs us are not in the majority.
Excellent case in point: Boehner's District in Ohio, in which the blue-haired retirees and their surviving spouses still automatically vote Republican and think Eisenhower may still be President, but are not sure.
The people who represent these reliable voters are in it for the money, the perks, and the pork. The country is the last thing on their minds. They made their deal with Democrats two generations ago and it still pays well.