How about this not-thoroughly-researched but possibly-mostly-correct summary:

• Republicans want 19th-century American weapons laws; Democrats want 18th-century European weapons laws.
• Republicans want 19th-century business laws; Democrats want 18th-century business laws (strict governmental control, strong workers' guilds).
• Republicans want 20th-century abortion law; Democrats want 1st through 19th-century abortion law.
• Republicans want 19th-century environmental laws; Democrats want medieval environmental laws (vast nature preserves which the population must leave untouched).
• Republicans want medieval taxation (special tax exemptions for the wealthy) or post-Augustinian Roman taxation (a flat head tax); Democrats want pre-Augustinian Roman taxation (taxation primarily of real estate).
• Republicans want a 20th-century American interventionist large military; Democrats want an 18th or 19th-century American isolationist small military.

The only pattern I see is that Republicans seem to have shorter memories.