Endurably
The Century Dictionary and Cyclopedia
In an endurable or durable manner; so as to be endured.
the GNU version of the Collaborative International Dictionary of English
adverb.
In an endurable manner.
Wiktionary, Creative Commons Attribution/Share-Alike License
adverb.
In an
endurable
or
tolerable
manner.
Word Usage
"A “reliable” vote, or a person who endurably believes in core conservative principles and supremacy of our Constitution."