And one thing that polls will surely have a hard time measuring: any rebound Joe Biden will come out of his fugitive victory in South Carolina on Saturday.
Here are five conclusions from the super Tuesday polls of the weekend:
Sanders leads in California, but others could reach the delegate threshold.
A CBS News Battleground Tracker / YouGov Survey Sunday morning shows Sanders with a significant advantage in the biggest Super Tuesday delegate award. The independent Vermont senator is 31 percent in the poll, ahead of Joe Biden with 19 percent, Elizabeth Warren with 18 percent and Mike Bloomberg with 12 percent.
That is not an advantage as big as a CNN / SSRS Survey on Friday that showed Sanders with 34 percent, with Warren second with 14 percent.
The distinctions here are important: only candidates who break 15 percent will win a proportional share of state delegates. If Sanders were the only candidate with more than 15 percent, he would win all state delegates, even if he obtained only one third of the votes.
But with two or three other candidates possibly joining Sanders above the 15 percent threshold, the delegates' route would be divided. CBS News estimates that under the scenario represented by its survey, with Biden and Warren also reaching the threshold, Sanders would earn slightly less than half of the available delegates.
Will Bernie also win Texas?
According to four polls published in the last 48 hours, Sanders enters as the favorite in Texas, the second largest state vote on Tuesday. But the race seems closer than in California, and Sanders' leadership is far from assured.
Sanders has a broad advantage in a NBC News / Marist Survey: 15 points over Biden, 34 percent to 19 percent. Bloomberg is third, with an important 15 percent.
But a CBS News Battleground Tracker / YouGov Survey It shows a much closer competition: Sanders leads Biden by just 4 points, 30 percent to 26 percent. Bloomberg is a surprising distance from the state delegate threshold, at 13 percent.
And a Dallas Morning News / Texas-Tyler University Survey It shows Bloomberg in a stronger position: Sanders leads Bloomberg by 8 points, 29 percent to 21 percent, with Biden very close at 19 percent.
The southern states resemble the battlefields of Super Tuesday.
What states are really at stake on Tuesday? Those who resemble, at least a little, South Carolina.
Alabama has a large proportion of African-American voters, and Biden, who won approximately 60 percent of the black vote in South Carolina on Saturday, will be the favorite there.
But in other southern states that have significant, but smaller, black populations, the race looks like a jumping ball. A NBC News / Marist Survey in North Carolina it shows Sanders (26 percent) and Biden (24 percent) essentially tied there, with Bloomberg in third place with 15 percent.
Then there is Virginia, where a Christopher Newport University Survey published on Friday shows Biden (22 percent) slightly ahead of Sanders (17 percent) and Bloomberg (13 percent).
There are not so many recent surveys in states like Arkansas, Oklahoma and Tennessee, but the demographic profiles of those states suggest that there are likely to be similar contests.
Can Warren stop Sanders in Massachusetts?
A Boston Globe Survey / WBZ-TV / Suffolk University published on Saturday shows the two liberals running side by side in Warren's home state. Sanders (24 percent) and Warren (22 percent) are far ahead of second-level candidates in Massachusetts: Bloomberg (13 percent), Pete Buttigieg (12 percent) and Biden (11 percent).
The situation is similar for Amy Klobuchar, who is trying to win her home state of Minnesota but is not registering in the surveys elsewhere. The most recent survey in Minnesota, since Minneapolis Star Tribune and Mason-Dixon, is a week old, but showed that Klobuchar endured Sanders, from 29 to 23 percent.
Don't look for signs of a Biden bounce in the polls.
We will probably have to wait until Tuesday night to see if Biden's good performance in South Carolina gives him momentum. All the surveys cited in this article were conducted before the first primaries in South Saturday.
Biden is trying to capitalize on South Carolina, and his campaign has a plan to boost his campaign with insufficient funds in places where Sanders and Bloomberg flank them, in particular.
However, there are limits on what an increase in Biden may have in some of these states, especially those with a solid early vote before the South Carolina primary. In California, most voters mail their ballots before election day. In Texas, 1 million people had already voted early in person until Saturday. In North Carolina, 792,000 voters have already cast their vote.
Still, there are some signs that Democrats have been holding back their ballots to see how the race would develop. In California, political consultant Paul Mitchell told POLITICO that he had seen a significant return of the ballots among regular primary voters, suggesting that they are waiting until the last minute. And in Texas, early participation in Republican primaries (1.1 million) is outpacing Democratic competition, even though there is no competitive race at the top of the Republican ballot.