In season one, Ned Stark is brought to the capitol city of Kings Landing to serve as the Hand of the King.
Ned quickly placed his trust in Petyr "Littlefinger" Baelish, the well-connected Master of Coin. This went very badly for Ned, as Baelish was more concerned with his own financial and political stability than advancing Stark's career.
Eventually, Baelish assisted the rival Lannister faction in arresting and eventually killing Stark.
The situation could hold a lesson for the Republican Party. In the wake of the 2012 election, many conservatives have claimed that the party trusted political consultants too much during the course of the election, and contributed to the GOP's losses.