There was a lot of talk about the 2014 Republican sweep, particularly how it was the largest R majority in the House since 1928. Michael Barone points out that the Republican and Democratic parties of today are quite different from their early 20th-century incarnations. The earlier Republican party was dominated by Northerners, political heirs to 19th-century Republicans who pushed for the Civil War. After WWII, they backed the expensive Marshall Plan. They passed the Taft-Hartley bill over Truman's veto, limiting the power of labor unions in ways that have lasted to the present.
The modern R-D split is still geographical, but characterized by a thin strip of D on each coast and a huge field of R in between. The Democrats by and large favor a strong central government; the Republicans are uneasy about the size of government but lack a unified strategy to alter it.
I see a 3-way split: big-tent strong government (populist/nanny state), small-tent strong government (crony capitalist oligarchs), and big-tent small government (libertarian/free marketists).