Early voting has begun in Texas and Ohio, the delegate-rich states which hold crucial Democratic primaries Tuesday.
Hillary Clinton is pinning the future of her struggling candidacy on wins in both states.
In Texas, Barack Obama is targeting urban areas, where early voting has swelled to record numbers. But there's also a heavy turnout in in Hillary Clinton's targeted areas, especially heavily Hispanic regions in South Texas.
The latest early numbers suggest Obama is seeing great success in the big cities, which have large delegate totals. Clinton hopes to get the smaller delegate numbers over broader areas of the state.
More than a-half million people in the 15 largest Texas counties have already voted. That's more than four times the turnout in 2004.
They're also voting early in Ohio. Election officials say the Democratic primary could surpass the absentee-ballot record even for a general election. That was more than 700,000 ballots in 2006.
Some analysts are saying the results in Tuesday's voting, which also include Rhode Island and Vermont, could make or break the Clinton campaign.