How long will Pawlenty last if he flames out in the Iowa straw poll?

The voting will not open for at least six months, but Mr. Pawlenty knows that his performance at the Iowa Straw Poll on Aug. 13 — fair or not — will help determine whether his candidacy accelerates or lands in the annals of Republican presidential hopefuls like Elizabeth Dole, Lamar Alexander and Dan Quayle whose campaigns were extinguished here.

The sense of urgency was apparent as Mr. Pawlenty made the case to Republicans that an experienced candidate was preferable to an intriguing one. If Michele Bachmann, his fellow Minnesotan, was on his mind, he did not say so directly, but there was little mistaking his point…

Few candidates make it to the White House without weathering a difficult period — as President Obama could testify. But Mr. Pawlenty has an extra set of challenges: he is building the best ground-level organization of any campaign around, but has struggled to tap into the new grass-roots energy coursing through the Republican Party and finding it difficult to secure early commitments because the field is still developing.

In an interview on Thursday, Mr. Pawlenty said he saw no reason to retool his campaign. “This is like a runway where you start to pick up speed and take off — I think that’s what we’re doing,” he said.