One: we ought to dramatically increase legal immigration. Years-long lines to become a citizen are dumb. Citizens not only pay taxes, they can also call on the government to enforce minimum wage laws and protect their right to unionize in order to raise wages (downward pressure on low-income wages is one of the negative effects of illegal immigration). All those people waiting in line on the other side of the border should get a quicker wait to become a citizen.
Two, reforming Mexico's political and economic structures are far more vital to the United States' self-interest than creating political and economic structures for Iraq. Did you know that every level of government in Mexico is under a term limit of one term? How screwed up is that? And the percent of people paying taxes is far lower than in other nations, because only the federal government collects taxes -- state and local governments do not. That distant Department of Revenue breeds resentment, corruption and tax evasion. It's time for some local tax authority as well.
Improving Mexico should be a top priority of ours.