1: destructive of life: Deadly.
2: injuring or endangering society: Pernicious.
3: causing displeasure or annoyance.
4: infectious, contagious.
– pestilently, adverb.
[Origin: Middle English, from Latin pestilent-, pestilens pestilential, from pestis.]
“Sir Richard was a pestilent innovator, it is certain. Before his time the Hall had been a fine block of the mellowest red brick; but Sir Richard had travelled in Italy and become infected with the Italian taste, and, having more money than his predecessors, he determined to leave an Italian palace where he had found an English house.” The Ash-Tree, Ghost Stories of an Antiquary, by M.R. James.
Note: It seems to me that pestilent innovator is a fine descriptor of Trump, although the ‘innovator’ might be a tad complimentary.