Mitt Romney's primary victories in Arizona and Michigan played out along now-familiar lines, with Romney faring better among moderate voters and those who said unseating President Obama was their highest priority.

As has been the case in previous primaries, more pragmatic voters focused on the White House selected Romney while voters who chiefly valued conservatism rallied behind Rick Santorum. In Michigan, voters for whom the most important quality in a candidate was can defeat President Obama -- about a third of the electorate -- chose Romney. Santorum handily won the combined 40% who most emphasized is a true conservative or has strong moral character.

Similarly, self-avowed very conservative voters in Michigan chose Santorum by a wide margin, while Romney carried the somewhat conservative bloc. When it came to party affiliation, Romney overwhelmingly won the three fifths of voters who were Republicans, while idependent voters were evenly split. (Santorum, whose campaign sent out a controversial robocall urging Democrats to vote for him in Michigan's open primary, easily won self-identified Democrats.)

Michigan voters seemed to respond to Romney's relentless focus on his economic credentials, as well as to Santorum's emergence as the more socially conservative of the two: voters who said the economy or taming the deficit mattered most, more than two thirds of the electorate, went for Romney, while Santorum won resoundingly among voters most concerned with abortion.

The Michigan results also underscored lingering concerns about Romney's struggles with blue collar or religious voters. Santorum edged Romney among households that make less than $99,999 annually, while Romney carried more affluent voters. Evangelical or born again Christians, about two-fifths of voters, chose Santorum.

Romney's victory margins among those demographic groups was less pronounced in Arizona, where the former Massachusetts governor captured virtually every subcategory en route to a nearly 20-point overall victory. But the results there affirmed the same narrative: voters most concerned with evicting President Obama chose Romney, and those concerned with moral integrity or conservative purity chose Santorum.

Similarly, the three quarters of Arizona voters who said they would definitely vote Republican in November chose Romney by a wide margin, but Romney's advantage was slimmer among voters who said they would cast a vote only if their chosen candidate won.