Certain functions clearly belong to the federal government, the state governments, and local governments. National security is a federal matter, the issuance of licenses is a state matter, and garbage collection is a local matter. One aspect of competitive federalism today is that some policy issues, such as immigration and the marital rights of gays and lesbians, have been redefined as the roles that states and the federal government play in them have changed. Another aspect of competitive federalism is that interest groups seeking to change the status quo can take a policy issue up to the federal government or down to the states if they feel it is to their advantage. Interest groups have used this strategy to promote their views on such issues as abortion, gun control, and the legal drinking age.