Ingraham thought Miers was too liberal. According to the Washington Post, Ingraham, along with her conservative peers, "didn't sink the Harriet Miers nomination on their own. But in the blink of a news cycle, they turned against their president, framed the debate and provided the passion that undermined her case."
In 2005, Miers withdrew her nomination.
Ingraham's relationship with the mainstream GOP didn't improve with presidential candidates John McCain or Mitt Romney, who both lost to Barack Obama.
Sources: Newsweek, The New York Times