"spine of steel" - "steel in his spine"

[powerlerner]

what does the above mean?

thank you very much..

[Anglika]

Without any context: said of a person of strong moral and intellectual strength.

[dilermando]

Without any context: said of a person of strong moral and intellectual strength.

Here is a bit of context. I am not powerlerner.

Saying that he knew the Illinois Democrat well from their time together on the campaign trail, Biden said of Obama, he "has the judgment, he has the intellect, which no one doubts, and I guarantee you he has the steel in his spine to lead this country of ours out of the deep hole we have dug ourselves into." [snip] Obama's spine of steel, McCain's mind of mush - City Hall - Election 2008

“She was a great influence,” said Donald Murie, one of Mardy and Olaus’ three children. “She has this sunlight aura that warms up the space around her. At the same time, she has a spine of steel and can nail you with her eyes.” Points West Article - Margaret Murie: Sunlight Aura and Spine of Steel

[Reemy]

what does the above mean?

thank you very much..

Someone has a spine of steel is someone has courage and willpower and oppositely for people who lack courage and willpower the term "spineless" would be quite descriptive.