- In late April, a Quinnipiac poll found that, taken together, just five candidates — Joe Biden, Bernie Sanders, Elizabeth Warren, Kamala Harris and Pete Buttigieg — drew 79% of the Democratic primary vote.
- Six weeks later, shortly before the first round of Democratic debates on MSNBC, those five drew the same 79%.
- This week, after the first round and just before the second, new Quinnipiac numbers showed that those five drew 78%.
The second round of Democratic presidential debates produced strong moments for multiple candidates, from Senate star Elizabeth Warren to the eccentric author Marianne Williamson.
Progressive candidates hit hard at their moderate rivals. "I wrote the damn bill," Bernie Sanders snapped at Rep. Tim Ryan about his "Medicare for All" proposal, while Warren dismissed former Rep. John Delaney for emphasizing "what we really can't do and what we shouldn't fight for."
The moderates gave as good as they got. Delaney stoutly challenged Warren as a Trump-style trade protectionist, while Gov. Steve Bullock derided "wish-list economics" and warned that working people "can't wait for a revolution" like the one Sanders calls for.
Did any of Tuesday night's action significantly alter nomination prospects for any among the 10 candidates on stage?
Will the skirmishes Wednesday night with another group of 10, including former Vice President Joe Biden and Sens. Kamala Harris and Cory Booker change the dynamics? After all, the volatile subject of race looms over their face off.
That might sound surprising considering the vast exposure nationally televised debates offer a sprawling field of candidates, each desperately seeking traction. But it makes more sense if you consider the possibility that voters have already culled the field six months before the initial nomination contests in Iowa and New Hampshire.
Recent national surveys by Quinnipiac University suggest as much. In late April, Quinnipiac found that, taken together, just five candidates — Biden, Sanders, Warren, Harris and Pete Buttigieg — drew 79% of the Democratic primary vote.
Six weeks later, shortly before the first round of Democratic debates on MSNBC, those five drew the same 79%. This week, after the first round and just before the second, new Quinnipiac numbers showed that those five garnered 78%.
Harris' strong attack on a shaky Biden in the MSNBC debate had a short-term impact. In a Quinnipiac poll taken immediately afterward, she shot up to 20%, from 7% in mid-June, while front-runner Biden fell to 22% from 30%.
But those effects have since eroded. Heading into Wednesday night's faceoff, Quinnipiac found that Biden's standing rebounded to 34%, while Harris slipped back to 12%.
Cause-and-effect links between political events and polling results are notoriously difficult to establish. Some of the movement could simply reflect the normal variations that margins of error produce. Some could reflect rising alarm over the behavior of President Donald Trump, heightening Democrats' desire for the familiar, comfortable alternative Biden represents.
But just as the attitudes of voters on all sides have hardened concerning Trump, they may have solidified over which potential Democratic challengers the party's primary voters will pay attention to. That would be bad news for a passel of serious-minded candidates who, so far at least, have proven unable to grab a solid foothold in the 2020 conversation.
Sen. Amy Klobuchar of Minnesota ranks among the most popular members of the U.S. Senate, boasting strong election victories in the kind of heartland state that gave Trump the presidency in 2016. She drew 1% of the primary vote in Quinnipiac's late April survey, and remained at 1% in late July.
During that same period, Booker has moved from 2% to 1%. Ryan and Delaney, Sens. Kirsten Gillibrand and Michael Bennet, Gov. Jay Inslee of Washington and former Obama Cabinet Secretary Julian Castro, all failed to register even 1% nationally this week.
Those candidates will face challenges in remaining on debate stages this fall as the Democratic Party ratchets up the polling levels and numbers of campaign contributors needed to qualify. More than the lost opportunity for one-liners, missing debates make it harder for also-rans to sustain financial oxygen.
Underdogs still can narrowly focus their attention and cash toward breakthroughs in the small states where voting starts. As a wealthy former entrepreneur, Delaney can keep campaigning in Iowa as long he wants to pay for it; Booker has assembled an especially strong Iowa campaign organization.
But there's no sign that's made them competitive so far. The current realclearpolitics.com average of Iowa polls shows Delaney and Booker with 1% and 2.5%, respectively.
Indeed, in the earliest states — Iowa, New Hampshire, Nevada and South Carolina — realclearpolitics.com shows the same top five contenders that national polls show. Democratic voters, with their attention and dollars if not yet their ballots, may already have determined the finalists for their party's nomination.