Yes Harris is a viable candidate who certainly has a chance. But when the initial euphoria dissipates, she has vulnerabilities. Particularly in the two areas of most concern to voters, according to polls. Crime and immigration.
Voters are sick of Blue State DAs who they view as soft on crime because they do not emphasize crimes against property. How will candidate Harris distance herself? Will she stress her career as Attorney General in California? That has its own pitfalls as she is remembered there for filling the prisons with non-violent drug offenders, and pushing for longer sentences so they could be used as state firefighters.
On immigration, as VP she was ostensibly placed in charge of security at the Mexican border. So does she own the crisis and vow to do better? Will doing so alienate the progressive wing? Both areas of vulnerability carry that downside.
Of course, this will only work if Trump doesn't shoot himself in the foot, which is a daily possibility.
*MySmiley*
"Bustin' makes me feel good!"
Ghostbusters, by Ray Parker Jr.