By Isabel Woodford, Carlos Vargas and Gabriel Araujo MEXICO CITY/BOGOTA/SAO PAULO (Reuters) – Latin America’s new “pink tide” is gaining pace after Colombia elected its first leftist leader Gustavo Petro, with Brazil expected to follow suit in elections in October, an echo of a regional political shift in the early 2000s. Around the region, angry voters, pinched by the economic impact of the COVID-19 pandemic and rampant inflation fanned by Russia’s invasion of Ukraine, have ditched mainstream parties and been lured by promised of bigger government and social spending. “A leftist government in…