Update 8:30 p.m.: Romney takes Arizona, leads in Michigan primary
Update 8:30 p.m.
WASHINGTON (AP) -- Mitt Romney coasted to victory in the Arizona primary Tuesday night and vied with rival Rick Santorum for supremacy in Michigan in a Republican presidential race as unsettled as the day it began.
Two other candidates, Newt Gingrich and Ron Paul, made little effort in either state, pointing instead to next week's 10-state collection of Super Tuesday primaries and caucuses.
Romney's Arizona triumph came in a race that was scarcely contested, and he pocketed all of the 29 Republican National Convention delegates at stake.
Michigan was as different as could be -- a hard-fought and expensive race in Romney's home state that he could ill afford to lose and Santorum made every effort to win.
Returns from 22 percent of Michigan's precincts showed Romney at 41 percent and Santorum at 38 percent. Paul was winning 11 percent of the vote to 7 percent for Gingrich.
In interviews as they left their polling places, Michigan voters expressed a notable lack of enthusiasm about their choices. Just 45 percent said they strongly favored the candidate they voted for, while 38 percent expressed reservations and 15 percent said they made the choice they did because they disliked the alternatives.
The lengthening GOP nomination struggle has coincided with a rise in Democratic President Barack Obama's prospects for a new term. A survey released during the day showed consumer confidence at the highest level in a year, and other polls show an increase in Americans saying they believe the country is on the right track.
Exit polling showed a plurality of Republican voters in both Michigan and Arizona saying the most important factor to them in the primaries was that a candidate be able to beat Obama in November. Romney won that group in Michigan, where it mattered most, and also prevailed among voters in the state who said experience was the quality that mattered most.
Santorum ran particularly well among voters who cited a desire for strong conservatism or strong moral character.
The polls surveyed both primary day and absentee or early voters. Interviews were conducted at 30 polling places in each state. Early results from Arizona's poll included interviews with 1,617 voters, including 601 absentee or early voters interviewed by phone. In Michigan it was 2,133 interviews including 412 absentee or early voters interviewed by telephone. The margin of sampling error for both polls was plus or minus 4 percentage points.