WASHINGTON — For some Republican presidential candidates, the party’s first three primary debates have been pivotal proving grounds that have strengthened their campaigns or shaken their supporters.

Ben Carson isn’t among them.

The famously mild-mannered Carson has largely avoided making headlines in the widely watched televised events, often willing to cede the spotlight to more verbose rivals and finding himself overshadowed in policy discussions. Yet the retired neurosurgeon’s standing with voters in preference polls has only gotten better.

“The political language and the traditional prism through which we evaluate candidates essentially does not apply to Ben Carson,” said Phil Musser, a Republican strategist.

It’s unlikely Carson will again shrink into the background Tuesday when the eight leading GOP candidates meet in Milwaukee for their fourth debate. Now viewed as a front-runner for the Republican nomination, Carson faces intense scrutiny about the veracity of his celebrated biography, which has been central to his connection with voters.