A member of the doctors' union, Lago was a pioneer in the performance of thoracic surgeries in the public health system of Maranhão and taught at the Medicine School of the State.

[3] Lago considered the expansion of the number of students in public schools and the improved training of teachers to have been his greatest achievements as the head the mayor of São Luís.

Counting initially on the support of only about 20% of the electorate, Lago surprised opinion polling and was elected in the second round with 51.82% of the valid votes against 48.18% of former governor Roseana Sarney.

[5] During his campaign, Lago bet on the political wear of the Sarneys, strongly denouncing the alleged corruption cases involving the group linked with them.

On March 2, 2009, the STF tried a lawsuit by the coalition of the defeated candidate Roseana Sarney and decided, by 5-2 votes, to revoke the terms of both Lago and Luiz Carlos Porto, the vice-governor of Maranhão and a member of the PPS.

Maria Clay was the State Secretary of Human Solidarity during the term of governor José Reinaldo Tavares, after his rupture with the Sarney family in May 2004.