Republican presidential hopeful Pat Buchanan is renewing his rivalry with aGeorge Bush, only this time it’s George W. — the Texas Governor — and notthe ex-President. Buchanan challenged the elder Bush in 1992 and again in1996. Now, Buchanan is running against the son.Buchanan says it’s too early to put “the crown” of the Republicanpresidential nomination on George W. Bush’s head.Buchanan says it’s premature for people to endorse Bush before finding outwhere the Texas Governor stands on the issues.Speaking this morning in Des Moines, Buchanan said he will build upon hissurprising, second place finish in Iowa’s 1996 Caucuses.Buchanan officially opened his Iowa campaign office today, with about threedozen supporters present.