Like Riginslinger, No way I would participate in a caucus.

Looking at demographics for the 12th-

Virginia- 7.7 million
Black 20%
Hispanic 6%

Maryland- 5.6 million
Black 29.5%
Hispanic 6%

Texas- 23.5 million   (March 4)
Black 12%
Hispanic 36%

Looking at past primaries, MD and VA will go for Obama, based on some 80% black vote for Obama; the white vote favoring Clinton but the young people for Obama. Many D. C. whites associated with the government live in VA; I have no idea who they will support but I don't think there are enough of them to strongly skew the results. Many of those associated with the military will be McCain or Huckabee supporters.

Texas will be extremely close, depending on the degree of participation by Hispanics. Candidates have not appealed to them directly, which is difficult because many, if not most, Hispanic Texans speak Spanish at home. The state has strong divisions. Based on California, I think the margin will be Clinton's.

I am posting my guesses (Democratic primary only) so that I can compare with the primary results and previous trends; they do not necessarily reflect how I would vote.