History 56 Social conditions 46 Emigration and immigration 40 Social aspects 34 Relations 22 Economic conditions 21 Noncitizens 20 more ... Drug control 18 Drug traffic 17 Government policy 16 Political aspects 16 Ethnic identity 15 Mexican Americans 15 Foreign relations 14 Violence 14 Ethnic relations 13 Border security 12 Illegal immigration 12 Immigrants 11 Boundaries 10 Group identity 9 Immigration enforcement 9 International relations 9 Politics and government 9 Ethnicity 7 Mexicans 7 Border patrols 6 Commerce 6 Free trade 6 International cooperation 6 less ...