In short, the 80 percent of House Republicans who are most conservative pose a grave danger to the 20 percent of House Republicans who are least conservative and represent less conservative districts. House Speaker John Boehner (R-Ohio) understands this, which is why he warns Republican members over immigration.
Rubio understands this, and if Hillary Clinton runs for president and Rubio runs for president, this will be clear when polls circa 2015 show Rubio running stronger against Clinton than the darlings of the right.
There could well be a majority of House votes in favor of immigration reform similar to the Senate bill, combining House Democrats and the least conservative House Republicans. Boehner could prevent a vote, but this would gravely endanger a number of House Republicans in 2014 and threaten GOP control of the House.
Republicans have alienated blacks. They are alienating Hispanics. They have alienated many women and young voters. A "white man's party" limited to conservatives is a road to permanent minority status for the GOP.
Marco Rubio knows this.
Marco Rubio is right.