Republican Gov. Chris Christie of New Jersey is walking a political tightrope as he charts his future, trying to balance his re-election campaign in a Democratic-leaning state with a potential presidential bid aimed at winning over Republicans. His latest challenge: appearing with former President Bill Clinton in Chicago at the risk of alienating religious conservatives being wooed in Washington by other potential GOP presidential candidates. Christie has pitched himself as a pragmatic, bipartisan leader as he seeks a second term as governor this fall. … In Washington the same day, evangelical conservatives gathered for Ralph Reed’s annual Faith and Freedom...