As the political world shifts its focus from primary speculation to running-mate speculation, general-election polling starts to take on the kind of salience it lacked in recent months. It's still very early -- Election Day is 174 days away -- and the presidential race is very likely to take multiple turns, but it's not too early to start establishing some baselines for future comparisons.
Take the new NBC News/Survey Monkey results, for example.
Attention is now rapidly moving to the hypothetical match-up between the leading candidates with an emphasis on a [Hillary] Clinton and [Donald] Trump contest. In this week's poll, Americans are nearly split between their choice of Trump or Clinton; her margin over Trump narrows from 5 points last week to 3 points this week to 48 percent to 45 percent. This early data indicates a very close race right now – though that may change considerably before November.
A closer look at the details reveals roughly what one might expect to see: men prefer Trump, women prefer Clinton. Those with less education back the Republican; those with more support the Democrat. Trump enjoys a lead among white voters, while Clinton enjoys even larger leads among every other racial and ethnic constituency.
This is obviously just one poll, and some of the others show the former Secretary of State with a more comfortable advantage. By one metric, Clinton's average lead is about six percentage points, which is hardly overwhelming, though it's triple the size of President Obama's lead over Mitt Romney on this day four years ago.
There is, however, one detail that's easy to overlook, and which may not be immediately obvious from looking at the top-line data: the race for the Republican nomination is over, which is more than Democrats can say.
Two weeks ago, on the night of the Indiana primary, Ted Cruz bowed out of the GOP race, and John Kasich exited a day later. This matters because Republican voters have had two weeks to rally behind their presumptive nominee, embracing the man who will lead the party's ticket in the fall. The efforts of the "Never Trump" forces notwithstanding, May has been a period of GOP voters coalescing.
The same cannot be said for Democrats. Bernie Sanders continues to campaign aggressively for the Dems' nomination; Hillary Clinton continues to split her focus between the primaries and the general election; and the Democratic race won't end for at least another month.
In other words, there's still a chunk of the electorate that's likely to vote Democratic in the fall, but which is saying, at least for now, that's it's not yet ready to support the Democratic ticket. It creates some asymmetry in national polling: Republican voters have had some time to line up behind their nominee, but Democrats won't have that opportunity until mid-June.
It's something to keep in mind as polls are released in the interim. Clinton's lead is modest, but it should grow a bit once she's the last Dem standing.