Pennsylvania Gov. Josh Shapiro is an electoral juggernaut in America's biggest swing state — and he's widely seen as a likely contender for president in 2028. But strategists in both parties question how tested he really is.Shapiro's success — he's cruised to victory in multiple statewide races — has come with an asterisk: He hasn't faced a well-financed opponent in recent contests, leading some political insiders to see him as more of a wildcard than his resume suggests.