  To investigate the effects of stellar feedback on the gravitational state of
giant molecular clouds (GMCs), we study $^{12}$CO and $^{13}$CO ALMA maps of
nine GMCs distributed throughout the Large Magellanic Cloud (LMC), the nearest
star-forming galaxy to our own. We perform noise and resolution matching on the
sample, working at a common resolution of 3.5 arcseconds (0.85 pc at the LMC
distance of 50 kpc), and use the \textit{SCIMES} clustering algorithm to
identify discrete substructure, or "clumps." We supplement these data with
three tracers of recent star formation: $8\mu$m surface brightness,
continuum-subtracted H$\alpha$ flux, and interstellar radiation field energy
density inferred from dust emission. The $^{12}$CO clumps identified cover a
range of 3.6 dex in luminosity-based mass and 2.4 dex in average $8\mu$m
surface brightness, representative of the wide range of conditions of the
interstellar medium in the LMC. Our observations suggest evidence for increased
turbulence in these clouds. While the turbulent linewidths are correlated with
clump surface density, in agreement with previous observations, we find even
better correlation with the three star formation activity tracers considered,
suggesting stellar energy injection plays a significant role in the dynamical
state of the clumps. The excess linewidths we measure do not appear to result
from opacity broadening. $^{12}$CO clumps are found to be typically less
gravitationally bound than $^{13}$CO clumps, with some evidence of the
kinetic-to-gravitational potential energy ratio increasing with star-formation
tracers. Further multi-line analysis may better constrain the assumptions made
in these calculations.
