For Democrats, Tuesday's results showed both candidates strengthening their natural bases of support, with Clinton exerting dominance among Latinos and Obama beginning to show progress among white voters.
In fact, Obama proved, just as he did in last month's Iowa caucuses, that many whites will vote for a black candidate.
After winning just a quarter of the white vote in South Carolina's heavily black primary last month, Obama needed to show that his support spanned the races. On Tuesday, he made that point decisively, beating Clinton in states with tiny minority populations: Connecticut, Minnesota, Utah, North Dakota, Alaska and Idaho. He won nearly half of white voters in California.
Those numbers could help Obama's campaign convince potential donors and voters in future contests in the coming weeks that he can go the distance, particularly with important primaries coming up in Washington state, Texas, Ohio and Pennsylvania.
For Clinton, Tuesday brought a clear consolidation of her strength among Latinos, a bloc she dominated in California. But exit polls showed Obama narrowing the gap in Arizona, where he won about 4 in 10 Latinos, and his victory in the Colorado caucuses suggests he mounted a successful courtship of Latinos in key areas of that state as well.
There were, however, some danger signs for Obama.
In Oklahoma, for example, an overwhelmingly white state won easily by Clinton, CNN exit polls showed that Obama won just 28% of whites. The result was similar in Tennessee, another so-called red state that Obama strategists have pointed to as a general election battleground should the Illinois senator win the nomination.
And although his campaign devoted a great deal of time and money courting Latinos in California, it seems he did not make much progress, losing the state's Latinos across all age groups.
Strengthening a Latino-black coalition could be crucial in a big upcoming primary in early March -- in Texas -- that many strategists now believe could be decisive.
Strategists for both Democratic campaigns said Tuesday they were encouraged by the results, but both said they expected the race to continue for weeks if not months as the campaigns scrap for delegates to the nominating convention.
"We're both prepared for a long, drawn-out affair," said Obama campaign manager David Plouffe.
