Trend: If your party nominated a generally well-qualified person for president who happened to be Mormon, would you vote for that person?

The exact percentage of Americans who resist the idea of voting for a Mormon has varied slightly over the eight times Gallup has asked the question, typically when a Mormon was running for president, including George Romney (1968 campaign), Orrin Hatch (2000 campaign), and Mitt Romney (2008 and 2012 campaigns). The percentage opposed to a Mormon president has averaged 19% since 1967 — from a low of 17% at several points to a high of 24% in 2007. The current 18% is down from 22% a year ago.

Gallup originally asked the question in April 1967, after Mitt Romney’s father, Michigan Gov. George Romney, announced the formation of an exploratory committee for the 1968 Republican nomination. At that point, George Romney was one of the two top contenders for the GOP nomination, along with the eventual winner, Richard Nixon.

Now, some 45 years later, George Romney’s son Mitt will be the Republican nominee — and the pattern of resistance to his Mormon religion has essentially not changed.