  The first James Webb Space Telescope ({\it JWST}) Near InfraRed Camera
(NIRCam) imaging in the field of the galaxy cluster PLCK G165.7+67.0 ($z=0.35$)
uncovered a Type Ia supernova (SN~Ia) at $z=1.78$, called ``SN H0pe." Three
different images of this one SN were detected as a result of strong
gravitational lensing, each one traversing a different path in spacetime,
thereby inducing a relative delay in the arrival of each image. Follow-up {\it
JWST} observations of all three SN images enabled photometric and rare
spectroscopic measurements of the two relative time delays. Following strict
blinding protocols which oversaw a live unblinding and regulated
post-unblinding changes, these two measured time delays were compared to the
predictions of seven independently constructed cluster lens models to measure a
value for the Hubble constant, $H_0=71.8^{+9.8}_{-7.6}$~km~s$^{-1}$~Mpc$^{-1}$.
The range of admissible $H_0$ values predicted across the lens models limits
further precision, reflecting the well-known degeneracies between lens model
constraints and time delays. It has long been theorized that a way forward is
to leverage a standard candle, however this has not been realized until now.
For the first time, the lens models are evaluated by their agreement with the
SN absolute magnification, breaking these degeneracies and producing our best
estimate, $H_0=75.4^{+8.1}_{-5.5}$~km~s$^{-1}$~Mpc$^{-1}$. This is the first
precision measurement of $H_0$ from a multiply-imaged SN~Ia, and provides a
measurement in a rarely utilized redshift regime. This result agrees with other
local universe measurements, yet exceeds the value of $H_0$ derived from the
early Universe with $\gtrsim90\%$ confidence, increasing evidence of the Hubble
tension. With the precision provided by only four more events, this approach
could solidify this disagreement to $>3\sigma$.
