Tentatively, I would say that the major issues are:
1. All legislation approving of and providing funds for the military operations.
2. Legislation which established the elaborate repressive machinery now in place (e.g. the Anti-Terrorism and Effective Death Penalty Act, or the National Defense Authorization Act).)
3. NAFTA
We would then have to analyze the impact of purely partisan interests on specific bills. Parties _do_ have to find ways to distinguish themselves from the opposition, regardless of the extent of agreement or disagreement on major issues of policy. Glen Ford suggests that the differences in campaign rhetoric all deal with cultue, not government policy.
This is not a complete or adequate list but it indicates the general procedure which would be required before deciding on differences between parties. Clearly, the vast majority of congressional votes are irrelevant. Deciding on the relevant votes is the heart of the question over party differences.
Carrol