bedrock issue

A topic or issue of sole, central, or fundamental importance. In geology, "bedrock" is the solid rock that lies underneath loose material like gravel or sand. When it comes to what voters care about most, the health of the economy will always be the bedrock issue. Reliable access to clean water is a bedrock issue for this rural community. Until that can be addressed, everything else is of second importance. Everyone should see their health as a bedrock issue. If you don't have your health, then what do you have?