US Presidential candidates vs. Westeros. (Spoilers all, ASOIAF).

Hillary Clinton, Bernie Sanders, John Kaisch, Marco Rubio, Ted Cruz, Ben Carson, and Donald Trump all individually replace Joffrey Baratheon* after the death of King Robert, and take up the Iron Throne. Just like Joffrey, the have the loyalty of the Lannisters (at least initially), but are widely perceived as possibly illegitimate by several other major factions. Assume their skillsets translate to Westerosi equivalents (Hillary's foreign policy relates to Westerosi nations, Cruz's Evangelical Christian support comes from the Faith of the Seven, etc...) Which candidate best handles the pitfalls of Westerosi politics and major challenges to their power?

Assume the following events are basically inevitable regardless of the candidates actions:

The War of Five Kings: Renly, Stannis, Rob, and Balon rebel against the Iron Throne, but compete against each other at the same time.

Targaryean Invasion: Aegon Targaryen and the Golden Company invade the Stormlands, eventually followed by Daenerys landing in Dorne with a combined force of Dothraki, Unsullied, Ironborne, and 3 dragons. Aegon and Daenerys are not necessarily working together.

Winter is Coming: The White Walkers bring down the Wall, and invade Westeros with their army of the undead, seeking to eliminate all human life.