Can CiviCRM do mass/bulk targeted e-mail "blasts" and "petitions" like Salsa, NationBuilder and other for-profit platforms?
It may help if you clarify the criteria around 'email blast to officials' but as I interpret it both 'send an email to an official' and 'sign up to a petition' can both be handled nicely using drupal webform and views.

Send an email to an official: will depend how automatically you want the target to be identified, but you could set up a View search, enter your postcode, get back a link to a webform that prefills cid2 to be the email for the designated official, and submission of the form triggers the email with or without the personal message.

Sign up to a petition: set up webform with a views block that will show eg 'number of petition signatures' and/or 'latest people to sign up' with a checkbox on the form that would allow users to indicate if they are happy for their name to show on the public roll.