Senate Republicans Tuesday proposed cuts to community health centers, national service, and grants to help children from low- and moderate-income families attend preschool as they unveiled the largest domestic appropriations bill, a $153 billion measure that’s sure to attract a veto threat from President Barack Obama. The author of the bill, Roy Blunt of Missouri, instead boosted the budget for the National Institutes of Health by $2 billion while awarding small increases to large programs giving grants to states for low-income school districts and special-needs children.