Novi, Michigan (CNN) -- As Mitt Romney admitted, they may not have been his prettiest wins.
"We didn't win by a lot -- but we won by enough, and that's all that counts," he said Tuesday night after victories in the Michigan and Arizona primaries.
Yet even in a cycle where he's already endured far more do-or-die contests than expected, these wins may be his most valuable yet.
Romney succeeded in both states when it counted most, largely on the strength of the same voting blocs that have consistently backed his campaign. The older, richer and better-educated you were, the more likely you were to vote for Romney. If you made your decision before the primary season began, or if beating President Barack Obama was your top priority, and the economy was your biggest concern, then Romney was your pick.
The outlook for Romney was sunny in the Southwest. He scored solidly with most Arizona demographics on his way to his more comfortable win of the night, winning pluralities in every age group, income level and major religious denomination, helped in part by overwhelming support from the state's sizable Mormon population. But it wasn't just a Mormon-fueled win: He even beat Rick Santorum among Santorum's fellow Catholics.
Debates mattered in Arizona, but early voting mattered more: More than half the state's voters said they had made up their mind before February began. And thanks to the early-voting option, 300,000 Republicans cast votes before Election Day arrived. Both of those groups broke heavily for Romney. Santorum may have had the wind at his back late in the race -- but thanks to the Romney campaign's organizational savvy, its candidate had already banked enough early votes to help him weather the storm.
In Arizona, where immigration issues take center stage, Romney's position on immigration -- the toughest of the remaining candidates -- helped him make major inroads with the state's most conservative voters.
But his stance didn't cost him with the state's Latino Republicans: Romney's 35% showing with that group was a roughly 50% boost over his support four years ago, when he ran against home state senator, John McCain. It also secured him a double-digit win over Santorum among that demographic.
There were some atypical results in Michigan, too.
It's impossible to say how much the roughly 10% of Tuesday night's voters who described themselves as Democrats were influenced by "Operation Hilarity," a liberal effort to sustain Santorum's candidacy by supporting him at the polls. But more than half of the Michigan Democrats who voted Tuesday backed the former senator from Pennsylvania, who managed a rare feat: winning the voting blocs on both ends of the ideological spectrum -- the most liberal voters and the most conservative. Romney had the edge with everyone else.
But the exit polls also contained some of the same warning signs that have plagued him since voting began.
About three in 10 of Tuesday's primary voters in Romney's home state described themselves as "very conservative," the key base of voters he's struggled to win over all year. That struggle continues: On Tuesday, half of those voters backed Santorum, while Romney managed a little more than a third. Evangelicals and the strongest tea party voters also supported Santorum.
And, just as in other states so far, Romney's vote total Tuesday night appears to have declined from his 2008 haul, on his way to an even narrower victory in a state where he had a years-long organizational head start and a 2-to-1 spending advantage over his closest competitor.
Even in Arizona, where Romney scored an easier win, Santorum still won a plurality of white evangelicals, voters most strongly opposed to abortion, and voters looking for a true conservative. And among the roughly one in five Arizona Republicans who said the religious beliefs of their presidential pick mattered "a great deal," Santorum ended the night with a double-digit advantage, winning 44% of that group to Romney's 33%.
Romney's wins may have moved his campaign a few vital degrees further away from crisis mode. But as the race moves to even bumpier terrain -- including Southern states with large evangelical populations that weren't 2008 wins for Romney -- Tuesday's results provide a glimpse of the scale of the challenge he still faces.