CONWAY, Pa. — The rules are workable enough in the right hands, in the right corner of a right-leaning region of a state like this one.

Avoid the jacket-and-tie look, so voters — wary enough of Democrats — do not think they are looking at a Jehovah’s Witness. “That happened,” recalled Representative Conor Lamb, now in a polo shirt.

Pivot to safe subjects. After a local here loudly mocked the idea of “Russian collusion” with President Trump to a peer, Mr. Lamb, 34, moved in to introduce himself, telling the man (who said he was Russian) about falling in love with Russian cuisine when he was in the Marines.

And if all else fails — and it will, often — there is always prayer.

“I was reading a little Isaiah this morning,” Mr. Lamb said at a town festival recently, approaching Paul Strano, 69, whose hat read, “F.B.I.: Firm Believer In Jesus.” The two bowed their heads.