Some politicians pride themselves on never flip-flopping, or otherwise changing their position. This is an extreme form of politics, but we have a perfectly good term for a set of beliefs that one holds without, or in the face of, evidence: a religion.
Successful religions tend to have beliefs that aren't susceptible to
checking against evidence (reincarnation, salvation) and precepts for the
faithful that have long term social value (honesty, kindness, fidelity.)
Unsuccessful religions tend to have beliefs that are easily found to be
false (creationism, global warming denial, supply side economics) and
sociopathic precepts (draconian punishment for minor crimes, torture for
political prisoners, tax cuts for the rich, hunger and death for the
While successful religions have often formed the backbone of long lived
cultures, religion is a really bad form of government, at least if you
think that a government should deal with the events it faces. So a
politician who prides him or herself on never ever changing has basically
self-identified as incompetent.
This is not a new problem. One of my favorite examples is Hiram Johnson,
who after saddling California with the disasters of initiative and
referendum spent decades in the Senate as a rigid isolationist, fighting
all attempts to prepare for WW II. Dunno if he'd come around by the time
he died in August 1945.
So here are two quotes about the merits of flexibility:
"Oh, Master, make me chaste and celibate - but not yet!" -Augustine
"When the facts change, I change my mind. What do you do, sir?" -Keynes