WASHINGTON (AP) -- Like so many voters before them, about half of Republicans who cast ballots in Wisconsin's presidential primary Tuesday doubt Mitt Romney's conservative credentials. But this they think they know: He's going to win the nomination.
About 4 in 10 GOP voters said the most important trait a candidate can have is the ability to defeat President Barack Obama in November, according to preliminary results of an exit poll in Wisconsin. And by an overwhelming margin, they believe Romney will be the candidate facing Obama.
The economy was the driving issue for Wisconsin voters, as it was to a somewhat lesser extent in Maryland, the surveys of voters found. Republicans also held a primary in the District of Columbia.
Voters Tuesday were among the least conservative to cast ballots in a primary season that saw the Republican race pulled sharply to the right. Even so, nearly half in Wisconsin said Romney was not conservative enough for their taste. More than four in 10 said the same in Maryland.
Romney's chief remaining rival, Rick Santorum, had no trouble convincing voters Tuesday of his ideological bona fides, and about 3 in 10 in each state described him as too conservative. But it was also apparent that the contest was about much more than that.
Lana Adikes, 65, made the cold political calculation that only Romney can defeat Obama, the man she voted for in 2008 but wishes she didn't, because of his health care law. "I think he's the only one who can do it," she said of Romney.
In the Milwaukee suburb of Brookfield, restaurant owner Earl Richter, 58, also felt that pull, but didn't give in to it. "I think anybody that can beat Obama is great," he said. "I think Mitt Romney will do just fine. But my principles or my beliefs are just more in line with Rick Santorum," so the former Pennsylvania senator got his vote.
The economy was cited as the top issue by a majority of voters in both states -- 6 in 10 in Wisconsin and just over half in Maryland -- and few said they see the economy on the upswing. Only about a quarter in each state said the economy is improving. The next most important issue in both states: the budget deficit, which shaped how more than one-quarter of the primary-goers voted.
The Supreme Court's hearing last week on the 2010 health care law brought that issue to the forefront of the nomination campaign. Santorum criticized Romney's record on the issue and appeared outside the Supreme Court to make the case that he is the candidate best suited to handle health care.
Wisconsin voters on Tuesday were split between Romney and Santorum as most trusted to manage health care policy, with about a third choosing each. About 1 in 6 said they trust Ron Paul most on the matter, 1 in 10 preferred Newt Gingrich.
About a third of GOP voters in each state said they were born-again or evangelical Christians.
In Wisconsin, Republican Gov. Scott Walker earned an 82 percent approval rating from GOP primary voters in the early exit polling. Walker will face a recall election in June.
Exit polls in Maryland and Wisconsin were conducted for The Associated Press and the television networks by Edison Research. This includes preliminary results among 735 Republican voters interviewed Tuesday as they left their polling places at 25 randomly selected sites in Maryland, and among 1,063 Wisconsin GOP voters as they left 35 polling places across the state. Results from Maryland have a margin of sampling error of plus or minus 5 percentage points; it is 4 points for the Wisconsin survey. D.C. voters were not surveyed.
Associated Press writers Dinesh Ramde in Whitefish Bay, Wis., and Carrie Antlfinger in Brookfield, Wis., and AP News Survey Specialist Dennis Junius in Washington contributed to this report.