Kamala Harris’ surging poll numbers: temporary or sustainable?

Vice President Kamala Harris’ first two weeks as a presidential candidate should give her campaign – and Democrats – quite a few reasons to be optimistic. 

Since replacing President Biden as the Democratic nominee, polls have shown a surge in support for Harris, particularly in the all-important swing states. Whether it lasts through November, however, remains to be seen.

Indeed, Harris has erased Trump’s lead in battleground states, with the vice president now slightly leading across...