MAY 2016: CLINTON +6. MAY 2012: OBAMA -3.

This is being touted as a worrisome poll for Hillary Clinton, because the race is tightening:

CBS/NYT national poll: Hillary Clinton's lead over Donald Trump narrows

... Hillary Clinton now holds a six-point lead over Donald Trump, down from 10 points a month ago.

Clinton still leads Trump in the Times/CBS poll, 47%-41%. I'll just point out that in mid-May 2012, Barack Obama trailed Mitt Romney in the same poll, 46%-43%.

Individual polls don't mean much, but the 2012 race, if anything, looked tighter in May than this year's race does. Here are the polls, from Real Clear Politics:



Obama had a few big leads, so he was clearly ahead, but Romney led in seven of the fourteen polls. (Oddly, one of Obama's big leads in May 2012 was in a Fox News poll, which had him up by 7; this week, a Fox poll showing Trump up by 3 is setting off Democratic alarm bells.) This year, there have been six polls in May, including the Times/CBS poll, and Clinton has led in four.

I'm seeing at Politico that Democratic Party insiders are worried about party unity this year. I'm worried too, obviously -- but in the Times/CBS poll, 14% of Democratic primary voters say they won't vote for Clinton, while 12% of Republican primary voters say they won't vote for Trump. That strikes me as a wash.

Now, the Times/CBS poll does tell us that 28% of Sanders supporters say they won't vote for Clinton in November. But (and I'm not the first person to point this out), in a May 2008 Times/CBS poll, only 60% of Clinton supporters said they'd vote for Obama.

Overall, 13% of Democratic primary voters that year said they wouldn't vote for Obama. And, in fact, according to the exit polls in November, 16% of Clinton-backing Democrats actually did vote for McCain. And yet Obama won.

Make of all this what you will. I think I overreacted to polls this week showing Trump in the lead. Trump's best poll, from Rasmussen, is certainly hinky:

New Rasmussen poll has Trump+5. It has Clinton winning less than 50 percent of non-white voters. Ahhh I missed Rasmussen...

— Nate Cohn (@Nate_Cohn) May 19, 2016

All this could get worse. But the averages are still in Clinton's favor.