Fast forward to Iowa 2016! PPP already polling.

[Mr. Morden]

Here are the full results:

Clinton 60%
Biden 18%
Cuomo 3%
Warren 3%
Schweitzer 1%
Warner 1%
O'Malley 0%
Patrick 0%

If Clinton doesn't run:

Biden 36%
Cuomo 14%
Warren 8%
Schweitzer 4%
Warner 3%
O'Malley 2%
Patrick 0%

If neither Biden nor Clinton run:

Cuomo 20%
Warren 11%
Warner 6%
Patrick 4%
Schweitzer 4%
O'Malley 2%

GOP:

Huckabee 17%
Santorum 17%
Christie 16%
Rand Paul 11%
Rubio 10%
J. Bush 8%
Ryan 6%
Palin 4%
Walker 4%

Here's PPP's 2016 Iowa poll from May:

https://uselectionatlas.org/FORUM/index.php?topic=153361.0

Very little change since then.  Clinton still has a huge lead.  Biden has actually gained a little.  Cuomo has a somewhat bigger lead in the scenario where Biden and Clinton don't run, but I think that's because they stopped polling Feingold, who had been 2nd in that scenario.  Clinton now does equally well among self-described liberals and self-described moderates.  She's at 63% among women and 55% among men.  In a reversal from the earlier poll, Clinton does better among voters under 45 than she does with olds, in part because Biden is catching on among olds (though still way behind Clinton).

On the GOP side, things are remarkably stable.  Huckabee and Santorum have exactly the same tie they had in the last poll, with Christie still 1 point behind.  Biggest change is Palin's decline.  She was at 10% in the last poll, but has now dropped all the way to 4%, a very anemic number for someone with such high name recognition.

[Mr. Morden]

GOP winners among each demographic group:

Tea Party member: Paul
not Tea Party member: Huckabee
not sure if Tea Party member: Christie
Evangelical: Santorum
not Evangelical: Christie
moderate: Christie
somewhat conservative: Huckabee
very conservative: Santorum
men: Santorum
women: Huckabee
Republicans: Santorum
Independents: Paul
age 18-45: Christie/Paul tie
age 46-64: Santorum
older than 65: Santorum

Democratic candidates' favorable/unfavorable ratings among Democratic voters:

Clinton 90/6 for +84
Biden 79/11 for +68
Warren 30/10 for +20
Cuomo 26/19 for +7
Patrick 10/9 for +1
Warner 10/10 for +/-0
O'Malley 4/8 for -4
Schweitzer 5/10 for -5

Republican candidates' favorable/unfavorable ratings among Republican voters:

Huckabee 68/20 for +48
Rubio 57/13 for +44
Santorum 65/22 for +43
Christie 57/17 for +40
Walker 50/12 for +38
Ryan 49/14 for +35
Palin 60/26 for +34
J. Bush 53/19 for +34
Rand Paul 49/29 for +20

Yes, Clinton has hit 90% favorability among Iowa Dems.  Again, have we ever had a candidate who started a campaign with such high favorables from their party, aside from an incumbent president?

On the GOP side, several candidates are seeing somewhat diminished favorability since May (Bush, Palin, and Paul being down the most), but Christie's favorability has actually gone up.

[Mr. Morden]

And either way, the Democrats don't tend to nominate someone who was a loser in a previous primary season, even if they seem popular later. They tend to elect up-and-comers, and do it a lot more than the Republicans do.

None of the Democratic primary campaigns from modern history feature a candidate who would be analogous to Hillary Clinton in 2016 though.  When have they ever had a candidate run who had favorability numbers like this when the campaign started?  When have they had a candidate run who lost the most recent competitive primary race by such a narrow margin?  Closest analogy would be Gary Hart running in 1988 after his close loss in 1984.  And Hart probably would have won the '88 nomination if not for his affair.

So yeah, it's possible that Clinton decides that she really means it about retiring from politics.  But if she does run, she'd be hella* tough to stop.

If she doesn't run, and Biden does, then I guess he starts out leading super-early polls like this, and thus the media would call him the "frontrunner".  But I think his popularity would prove to be more soft (though not as soft as Lieberman's support in the early polls from the 2004 race), and he'd probably end up being overtaken by someone else.

*Gratuitous Eric Cartmanism.

[Mr. Morden]

Here's the problem with the 2016 Hilary Clinton candidacy: she is deeply unlikable in many circles.

?

She's currently about the most popular politician in the country.  Obviously, some of that popularity would fade if she got back into partisan politics, but still, the above seems highly questionable.  And we're talking about the Democratic nomination here.  She has a 90% favorable rating among Iowa Democrats.  When have we ever seen a candidate start with numbers like that, aside from incumbent presidents?