One of the more interesting bits of conventional wisdom this primary season has been the belief that a lot of Biden’s primary advantage has to do with name recognition. Following this theory to its logical conclusion, Biden would lose ground as the primary season goes on.

Yet Biden’s mostly held his 30%. (Warren’s been gaining ground mostly at the expense of other candidates.)

Indeed, outside of some big event, our poll suggests that Biden’s floor may be stabler than others.

The majority of his voters (59%) say they will definitely support Biden in his fight for the Democratic nomination. Only 41% say they might change their mind.

For all voters of the other candidates, it’s reversed: 40% say they will definitely back their candidate and 60% say they might change their mind.

When you take a look at the horserace among voters who say they have definitely made up their mind, it’s Biden at 47%, Sanders at 25% and Warren at 11%. Among those who say they might change their mind, it’s Warren at 25%, Biden at 24% and Sanders and Buttigieg at 8%.

This looks very similar to what we saw in our last poll of likely caucusgoers in Iowa: Biden and Sanders do best among those who are certain of their choice. Warren does far worse.

That makes some sense, given Warren has gained a lot of supporters recently, and they may be more likely to switch away from her. Meanwhile, Biden and Sanders backers have been with their candidates for longer.