Not only would the New York billionaire probably have to transform previously safe Democratic territory in the rust belt, such as Pennsylvania and Michigan, as well as the more finely balanced Ohio, but he would also have to stop Clinton dominating in more diverse states such as Virginia and Colorado and possibly winning back Arizona and Georgia from Republicans.

But other experts, such as Larry Sabato of the Center for Politics at the University of Virginia, worry that Clinton’s struggle to conclude the Democratic race could make for a bumpy party convention that will yet dent her prospects in November.

“How she handles Sanders is key. If she does it skilfully, it will be crucial to motivating younger voters, who are very hard to get out to vote if they are not enthusiastic,” says Sabato. “If he wins California, it guarantees he will go forward to the convention trying to turn every last delegate – and it could be very damaging for her. It is a turning point.”

Just as importantly, he argues, Clinton needs to go on the offensive and set her own agenda over the next few weeks. “Some things she can’t control. She can’t control the FBI. She started that ball rolling and will have to live with the consequences,” adds Sabato. “She has to demonstrate how she is going to attack Trump. They are all over the map at the moment because there is an embarrassment of riches, but there is devilry in that, in a way.” Right now, most pundits agree that it all makes for a noisy political environment in which it is hard to judge who is really winning on a day-to-day basis.