as John McCain’s ‘pitbull in lipstick’

[dilermando]

From Watch out Obama - I'm a pitbull in lipstick, says barnstorming Sarah Palin | Mail Online

Sarah Palin recast herself as John McCain’s ‘pitbull in lipstick’ early today to defy her detractors and crown a rollercoaster week with a barnstorming speech to accept the Republican Party’s vice-presidential nomination.

1) what Sarah Palin meant with "I'm a pitibull in lipstick."?

2)What does "crown a rollercoaster week" mean?

[Anglika]

#1 She is metaphorically comparing herself to a pitbull terrier, dogs bred for dogfighting and notorious for their trait of holding onto whatever they bite. She is suggesting she never lets go once she gets a hold on something.

#2 To crown something means to acknowledge it to have reached the highest or perfect state.

rollercoaster week - a week in which events went from high to low to high points.

To crown a rollercoaster week = the week's final event is a high point.