favorite son

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A man favored for nomination as a presidential candidate by his own state delegates at a national political convention.
• noun A famous man viewed proudly by his hometown for his achievements.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun US A politician whose electoral appeal derives from his or her regional appeal, rather than his or her political views

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a United States politician favored mainly in his or her home state