A former Peronist, she was a member of the New Party Corrientes (PANU), but was expelled in 2009 due to her support to the Argentine National Government in the farm tax hike issue.

She was appointed to the Senate in 2006 upon the resignation of Romero Feris who was unable to take his seat due to ongoing court proceedings, having been elected in his own right in 2003.

[1][2] In the Senate, Viudes voted for the controversial Resolution 125 which had escalated the 2008 Argentine government conflict with the agricultural sector.

Although the motion was defeated on the casting vote of Vice-President Julio Cobos, Viudes was expelled by the New Party which maintained its opposition to the national government.

In February 2009, it was made known that she would be joining the ruling Front for Victory parliamentary group in the Senate and there was speculation that she would re-join the Justicialist Party.