No she didn't. Democrats did that by winning and McCain by losing.
If McCain won and Sarah was VP the conservatives as republicans would be even MORE demoralized than under Bush. Not saying she would be the cause, but there would have been complete disillusionment by Palin conservatives as 1) they cut deals and signed Pelosi bills , and 2) the McCain administration sunk to Bush approval lows in a few months much faster than Obama did being blamed for everything bad, again. There are many reasons this would have happened.
Now conservatives are united against democrats, in fact even RINOs are too. Not seeing where Palin made a difference this year at all. There was no Palin in 1993 and 1994 when RINOs got purged from party leadership. She is not calling the R party to task at all! She is just joining the "Obama is bad" theme. That is just swimming downstream. no guts, all glory! And it wont sell.
You can’t just change reality, conservatives had one thing going for them after Obama won in Nov, 2008 and that was Governor Palin, the media kept focused on her and she kept holding her own, which gave conservatism a presence during the Obama adulation and power grab, her spark kept us in the game and in a few months she started influencing even moderates like Rick Perry to become more emboldened, and even swaggering with remarks like “secession”.
Palin was firing up conservatives and helping to elect people like Sen. Saxby Chambliss. Instead of being broken and demoralized while the party and the media focused on Mitt Romney as the natural leader of the right, Palin kept us on the front pages and helped create an aggressive, confident, conservative, counterpoint to the normal narrative and roles, that the media and the Rockefeller/Romney GOP would have taken.
Regardless of your own goals and intents, there is a reason why conservatives support Governor Palin, and why she is the Key Note speaker at the National Tea Party Convention.