PPP's newest national poll finds Hillary Clinton leading all of her potential Republican candidates by between 7 and 10 points. She has 7 point advantages over Rand Paul (47/40), and Rick Perry and Marco Rubio (48/41). She has 8 point advantages over Ben Carson, Chris Christie, and Scott Walker all at 48/40. Her advantage over Mike Huckabee is 9 points at 50/41, and she's up 10 points each over Jeb Bush and Ted Cruz at 50/40.
What's really striking about Clinton's numbers against the Republicans is how steady they are no matter who she's pitted against. Clinton is between 47-50% against all 9 of the GOP hopefuls, and each of the GOP hopefuls is polling at either 40 or 41%. This is quite different from 2012 when Mitt Romney tended to be a good deal stronger against Barack Obama than all of the other GOP contenders.
There is a pretty big electability difference on the Democratic side though. In the off chance that Clinton were not to run for President, both Joe Biden (45/39) and Elizabeth Warren (43/41) would trail Jeb Bush in hypothetical contests. We've pretty consistently found Clinton running about 10 points better against the Republican field than potential Democratic alternatives.
There's been a lot of debate about the impact George W. Bush's unpopularity might have on the Presidential contest, but he's not nearly as unpopular as he used to be. Americans are pretty evenly divided in their feelings about him with 45% rating him favorably to 46% who have an unfavorable opinion. That actually makes him a good deal more popular with the public than his brother- Jeb Bush registers right now at a 29/45 favorability. Although President Bush may not be a huge liability, he's not an asset in the way Bill Clinton has the potential to be for Hillary either. President Clinton has a 49% favorability rating, higher than any Presidential candidate for next year, with 42% viewing him unfavorably.