Mexico's López Obrador is delivering the populism he promised

AMLO at the closing rally of his campaign. Photo: Alfredo Estrella/AFP/Getty Images

When Andrés Manuel López Obrador triumphed one year ago, it was unclear whether Mexico had elected the revolutionary populist from the campaign trail, or the more pragmatic figure from his tenure as mayor of Mexico City. We may now have the answer.

The latest: Finance Minister Carlos Urzúa excoriated the leftist president on Tuesday, penning a resignation letter that accused him of failing to base policy on evidence and empowering ideologues over experts.

Mexico's finance minister resigns, pushing peso to biggest fall in 4 weeks

Carlos Urzua Cordero. Photo: PEDRO PARDO/Getty Images

The Mexican peso fell 1.3%, the largest amount in 4 weeks, against the U.S. dollar on Tuesday after Mexico's Finance Minister Carlos Urzúa resigned unexpectedly.

What happened: Urzúa sent a letter to Mexican President Andrés Manuel López Obrador in which he suggested members of the president's inner circle with "patent conflict of interest" had meddled in policy and that decisions had been made without "sufficient foundation."