The Washington Post leads with news that, on the eve of his visit to Mexico, President Obama imposed financial sanctions against three Mexican drug cartels by adding them to the list of foreign "drug kingpins." The move not only allows the government to seize the cartels' assets, but also makes it easier to prosecute any American who provides support to the organizations. The Los Angeles Times also leads with Mexico, but takes a look at how the country has quickly "arisen as a foreign policy emergency" for Obama, who is likely to face pressure from Mexican leaders to move beyond talk of friendship and provide concrete help in several areas that go beyond the drug war. The New York Times leads with a look at how China is working hard to increase its influence in Latin America by offering much-needed capital to struggling countries in the region. After years of being ignored by the Bush administration, many are snapping up the large amounts of money being offered by China, which has quickly grown into the region's second largest trading partner. "This is how the balance of power shifts quietly during times of crisis," a former Commerce Department official said. USA Today leads with a controversial new article by two Army mental health researchers who say the military is focusing too much of its efforts in identifying mild cases of traumatic brain injury among combat veterans, at the expense of other medical problems. This has led many common symptoms to be identified as the result of TBI when they're more likely due to other problems, such as depression and post-traumatic stress disorder. The Wall Street Journal leads its world-wide newsbox with Obama's vow to simplify what he described as the "monstrous tax code," and notes that the White House is considering a plan that would free up to 40 percent of Americans from having to file tax returns. The announcement came on the same day as thousands of Americans gathered at "tea parties" across the country to protest against the president's Policies.