As 10 Democrats prepare to face off in Thursday’s presidential debate, the Economist/YouGov Poll finds Massachusetts Senator Elizabeth Warren in the best position among Democratic primary voters. She continues to be the best-liked candidate and is tied with former Vice President Joe Biden when voters name their first choice. Warren is also the only candidate a majority of voters say they are at least “considering” for their vote.

But she also goes into the debate with high expectations. One in three Democratic voters say they believe she will do the best job in the debate.

In both of her previous debates, voters said Warren performed best.

Thursday’s three-hour debate will certainly test the candidates, who just last week participated in a CNN-hosted town hall on climate change. The test may be tougher for the three current leaders in the race, who are also the three oldest candidates (Biden is 76, Vermont Senator Bernie Sanders is 78, and Warren just turned 70).

Warren’s gains in the last week as the first choice for one in four Democratic primary voters puts her in a tie with Biden on this question. Warren leads him when voters are asked which candidates they are considering. On that question, 55 percent name Warren, 48 percent Biden. Sanders is third on both measures. This week, the average Democratic voters is considering three candidates.

Presidential politics

Last week Biden led Warren by five points on the first choice question; then as now, Warren was the best-liked and most frequently considered candidate. No candidate who will not be included in Thursday’s debate scores in double digits on the question of whom voters are considering supporting, and the non-participants are all at 1 or 2 percent (or even less) on the first choice question. Half the candidates that are in the debate don’t register well. Just a few of the bottom half of the Democrats on Thursday’s debate stage are named by voters as their first choice.

Warren is the first choice of a third of liberal Democratic voters; Biden the first choice of a third of those who call themselves moderates. But nearly twice as many Democratic voters call themselves liberals (56%) as say they are moderates (31%). Biden is well ahead at the moment with African-American voters. Nearly half of them say Biden is their first choice. Only one in 10 Black Americans select a black candidate on that question.

It is important to note that half of those who say they will be voting in Democratic primaries or caucuses aren’t yet paying a lot of attention. Among that most attentive group, Warren leads Biden by 10 points (32% to 22%), with Sanders in third with 15 percent. Biden’s support rises among those who have paid less attention so far.

Warren’s comments at the climate change town hall – as well as her frequent claims that “I have a plan for that,” have convinced many Democratic voters that she does have an effective plan to combat the effects of climate change. More than two thirds, (68%) of Democratic voters say she does have an effective plan and just 7 percent disagree. Sanders does just about as well: by 65 percent to 9 percent, Democratic voters say he has a plan. Fewer than half of Democratic voters credit any other Democratic candidate with an effective climate change plan, although California Senator Kamala Harris and Biden come close.

As for the president, whom many think of as a climate change denier (43 percent of the public in a March Economist/YouGov Poll said President Donald Trump did not believe the Earth’s climate was changing), by two to one Americans say he does not have a plan for dealing with its effects. Less than half of Republicans think the president has an effective plan for a climate change response, while nearly a third of Republicans believe he does not. Eight in 10 Republicans accept that the climate is changing, though most of them do not attribute the change to human activity.

Whomever gets the Democratic nomination will have to run against the incumbent, whose defeat Democratic voters prioritize over agreement on policy. Democratic voters have always thought that Biden, if nominated, would defeat Trump. That is still true. But Warren now does just about as well as Biden on this measure. A majority think Sanders could win, too. Other candidates don’t do as well in Democratic voters’ perceptions.

Democratic voters are looking forward to Thursday’s debate. More than half say they will watch, and three-quarters believe debate performance will be at least somewhat important in their voting decision. A majority think this debate’s smaller size was the right decision, and 73 percent are looking forward to even more debates.

Related: Should Puerto Rico become America's 51st state? Most say yes

See the full toplines and tables results from this week's Economist/YouGov poll.

Image: Getty