New Triumvirate power wank
First, allow me to extrapolate on what makes the relevant quote so impressive.
After the Sacking of Coruscant, Aryn Leneer returns to occupied capital and senses this:
Due to her empathic sense, Aryn felt the dread in the air as a tangible thing, a pall that overhung the entire planet. It wore on her, weighed her down. The towers of duracrete and transparisteel seemed ready to fall in on her. She felt hunched, tensed in anticipation of a blow. The dread was omnipresent, an entire planet of billions of people projecting raw emotion into the air.She could not wall them out. She did not want to wall them out. The Jedi had failed them. She deserved to feel what they felt.
- Decieved
Whilst fighting Sith Sabers on Dromund Kaas, Luke Skywalker senses this:
Luke and Jaina were fighting back-to-back. The Sith attacking them had two advantages. One was the fact that they outnumbered the two Jedi. The second was that they were being reinforced by the emanations of the dark-side nexus within the temple. It surged forth like psychic sewage, clogging the Jedi's reflexes as it fueled their enemies.
- Fate of the Jedi: Ascension
This is stated to be the state of the Republic during the Dark Wars:
The Sith seemed to have achieved the victory they had long sought. Less than one hundred Jedi, nearly all of them in hiding, survived the Sith's purge. Many citizens took this unimaginable event as proof that the Force had turned malevolent, or that cosmic balance was nothing more than a story for children. Despair was palpable, and many planets offered only halfhearted and ragged defense against Sith attackers. Planets throughout the slice surrendered, and the Sith fed on the psychic misery of a shattered Republic.
- The Essential Atlas
Essentially, the Triumvirate manufactured a dark-side miasma across the entire Republic.