The End of Marco-mentum

After Mitt Romney lost in 2012, the G.O.P. undertook an “autopsy” to determine how it should best adapt to the changing American electorate. If Republicans were intent on appealing to young voters and being more inclusive of minorities, especially Hispanics, Rubio represented a model face of the idealized Republican future — at least as it was imagined by the Republican Party leaders and many conservatives in the news media. To them, immigration reform was a kind of magic bullet that would allow the G.O.P. to expand its base and address the prescriptions of their autopsy while keeping the rest of the platform essentially unchanged.