He also indicated interest in an economic agreement with Petrobras, Brazil's oil company. By giving more economic freedom to Pemex, investors say Peña Nieto's proposal could allow joint ventures and private investment in the oil company. According to the "Financial Times" in 2012, Peña Nieto's PRI government, which held just over 38% of the votes in Congress, might have difficulty gaining a majority to pass such reforms, or the two-thirds majority needed to change the Mexican constitution. Pemex was founded through the nationalization of foreign oil interests, and the Mexican constitution bans major outside investments. Changing Pemex could transform the psychology of Mexico's business sector and involve cultural and political changes that cannot be rushed. President Lázaro Cárdenas seized foreign oil company assets in 1938 to form Pemex, which has served as a symbol of national identity. Eric Martin of "Bloomberg News" stated that if Peña Nieto wants to invite investment, he will have to face the challenges of union leaders and local officials who have benefited from the oil company's bonanza. Productivity in Pemex has been declining since 2004. Peña Nieto declared while campaigning that overhauling Pemex will be the PRI's and his "signature issue", and that he will encourage private companies to invest in exploration and development activities. Following Peña Nieto's hike in the price of gasoline as a result of his privatization of the Mexican oil industry, protests erupted nation-wide. Protestors blockaded major highways, forced border crossings to be closed and shut down gas stations. Peña Nieto invited U.S. Republican presidential candidate Donald Trump to visit on 31 August 2016, and appeared with him in a press conference. Peña Nieto was criticized for extending the invitation to Trump, and following the conference, journalist Jorge Ramos criticized Peña Nieto for not using the opportunity to publicly contradict Trump's campaign promise to make Mexico pay for his proposed Mexico–United States border wall, as well as Ramos called Trump's "attacks on Latin American immigrants, his rejection of free trade agreements and his scorn for global organizations." Despite this, Peña Nieto stated on his Twitter that he made it clear to Trump that Mexico would not pay for the wall, only to shortly after get a reply from Donald Trump saying: "Mexico will pay for the wall!" Peña Nieto and Trump were to meet on 26 January 2017, until Trump wrote on his Twitter account: "If Mexico is unwilling to pay for the badly needed wall, then it would be better to cancel the upcoming meeting".