In the modern political system, which issue represents a basic disagreement between republicans and democrats?

There are several different issues that cause disagreement between Republicans and Democrats including:

1) Size of the federal government - Republicans prefer a smaller, less involved government while Democrats favor a large, more involved federal government.

2) Taxes - Republicans favor a low tax rate on individuals, corporations, and businesses. Democrats prefer a higher tax rate on wealthier companies and individuals and a lower tax rate for poorer citizens.