The "Palestine" issue is single-issue on the surface, but it is often used because it is a succint way to package a broad set of desired foreign policy changes: more cooperation with the Islamic world, less aggression/hegemony, and less money fed to insatiable MIC.
Personally I do not see how we can afford to maintain the MIC for much longer, so these issues are very important to me.
The reason we can afford it is due to our GDP. We aren't that far ahead of other developed countries when you look at it as a percentage of GDP. The real issue is our debt, for which the interest payments are almost as much as our defense budget while adding nothing to the economy. But neither side is serious about tackling this issue.
Personally I do not see how we can afford to maintain the MIC for much longer, so these issues are very important to me.