National polls remain a less-than-ideal way to measure the presidential horserace, but they are often the quickest way to compare where today’s race stands to campaigns of the past. We can compare where Donald Trump and Hillary Clinton stand right now to the past 3 national campaigns. It’s not a pretty picture for Trump.
First, the poll averages. Trump now stands at 38.6% in the RealClearPolitics national poll average; that’s down almost five points in three weeks, but Trump has never polled above 44.3% in the average, which he hit on December 5, 2015. His low was 33.7% on July 1, 2015, when he was just getting started. Hillary Clinton is at 44.1%, but has never been below 43.2%, where she was when Trump nosed ahead of her momentarily on May 23, 2016, while he was enjoying his “bounce” in the period between Trump clinching the delegates for the GOP nomination and Hillary clinching for the Democrats.
How unusual is it for a presumptive nominee to be polling below 40%? In the last three elections, unheard-of in the polling average, and rare even in individual polls:
Mitt Romney in 2012 never polled below 41.5%, which is where he entered the race on February 3, 2011; his low during 2012 was 43.0% on August 12, 2012.
John McCain in 2008 hit a low of 38.3% on October 26, 2007, but cleared 40% after November 15, 2007 and never fell back below it, bottoming out in 2008 at 40.3% right around this time (i.e., after Barack Obama had finally put away Hillary), on June 29, 2008.
George W. Bush in 2004, the last Republican to actually win a presidential race, never polled below 42.7% on July 19, 2004, which was right on the eve of the Democratic Convention.
What about the Democrats?
Obama in 2012 hit his low point in late May, 45.4% on May 28, 2012. Like Bush, of course, he benefited from running as an incumbent.
Obama in 2008, the last successful non-incumbent, never polled below 43.2% on January 31, 2008, in the heat of the Democratic primaries.
John Kerry in 2004 bottomed out at 42.0% on April 27, 2004, just before the Abu Ghraib story pulled Bush down from a persistent spring lead.
Now, let’s look at individual polls. How many times has each candidate polled below 40%?
Trump: 25 of 83 (30.1%), 15 of 45 (33.3%) in 2016, 10 of 38 (26.3%) in 2015.
Hillary: 5 of 83 (6.0%), 4 of 45 (8.9%) in 2016, 1 of 38 (2.6%) in 2015.
Romney: 15 of 326 (4.6%), 4 of 202 (2.0%) in 2012, 11 of 124 (8.9%) in 2011.
Obama 2012: 0 of 326 (0%), 0 of 202 (0%) in 2012, 0 of 124 (0%) in 2011.
McCain: 32 of 319 (10.0%), 21 of 264 (8.0%) in 2008, 11 of 55 (20.0%) in 2007.
Obama 2008: 6 of 319 (1.9%), 0 of 264 (0%) in 2008, 6 of 55 (10.9%) in 2007.
Bush: 1 of 233 (0.4%), 1 of 232 (0.4%), 0 of 1 (0%) in 2003.
Kerry: 3 of 233 (1.3%), 3 of 232 (1.3%), 0 of 1 (0%) in 2003.
As you can see, the frequency of national polls rose dramatically from 2004 to 2012, and has fallen off a lot this year, even considering that the general election race has really just started. But there’s no way to look at Trump’s national polling that avoids the grim reality that he is at a lower ebb than any general election candidate has hit in the last three elections, and has been for most of the time since last summer. Even if we assume that Trump’s ceiling in the polls is higher than his sky-high unfavorables would suggest (as was the case in the primaries), his floor is the lowest of any recent nominee.