The Republican presidential primary is effectively tied between Mitt Romney and Mike Huckabee—with Sarah Palin trailing them both by substantial margins in the Republican presidential trial heat.

The prospective addition of Donald Trump to the race did produce some impact, and his support was in the high single digits.

Individual head-to-head ballot tests for president show President Obama with a double-digit lead over Sarah Palin (51-40), a narrow lead over Mitt Romney (49-47) and Donald Trump (43-41), and a tie with Mike Huckabee (46-46).

Moreover, the particularly high percentage of undecided voters in the race with Trump underscores the substantial degree of uncertainty his prospective candidacy provokes.