Tuesday races promise easier interpretation

Keys for Obama
Critical constituencies for Mr. Obama include young voters and African-Americans. One remarkable feature of his Iowa and South Carolina victories was that voters younger than 30 turned out as heavily as those 65 and older.

Mr. Obama is counting on heavy turnout in university towns like Austin and Columbus.

Because of the apportioning of delegates, African-Americans in Ohio and Texas could matter more than their estimated 15 percent share of the electorate would suggest.

That is why urban centers like Cleveland and Houston are central to his strategy. His strategists are also watching blue-collars towns like Akron and Youngstown to gauge their success at peeling working-class voters, especially men, away from Mrs. Clinton.

Independent influx
With a long track record in Democratic politics, Mrs. Clinton prefers contests limited to party regulars. Mr. Obama has held the upper hand among independents.

Independents can vote in all four primaries on Tuesday. Experts do not expect the reach their level in New Hampshire, more than 40 percent.

Texas and Vermont have no party registration. Ohio and Rhode Island let independents in either primary.

Unseen factor
Although big states dominate the headlines, small ones sometimes have an outsize role in the count for nominating delegates. Mr. Obama leads Mrs. Clinton by roughly 150 delegates, depending on who is counting. He remains far short of the 2,025 needed for the nomination.

Because Democrats allocate delegates in primaries in proportion to the popular vote, close contests sometimes leave the candidate who finishes second in the popular vote with virtually the same number of delegates as the winner.

Tiny Vermont, with one-tenth the delegates at stake in Texas, could have a larger effect on the delegate race by adding as many as five to Mr. Obama’s lead if he wins by a large margin there.

Working the process
Mr. Obama, a one-time community organizer, has dominated caucus contests that place a premium on political mechanics. The good news for Mrs. Clinton is that the four states have primaries. The bad news is the Texas Two-Step, which will include evening caucuses to select one-third of the delegates. Though Mrs. Clinton is competing more aggressively in those caucuses than in some earlier states, a chance remains that she could win the primary vote but lose enough delegates in the caucuses as to cast doubt on who “won” the state.

The more caucus turnout increases, the greater the challenge for Texas Democrats to administer a process that insiders usually dominate. Ohio officials, criticized for their oversight of balloting in the 2004 presidential contest, will face similar tests if turnout surges as it has in earlier primaries.

Putting on a good face
Campaigns always like as much attention as possible for their victories. Sometimes how quickly the news media report them determines that.

Pre-election polls point to a lopsided race in the state with the earliest poll-closing time, Vermont. That could produce good news for Mr. Obama soon after its polls close at 7 p.m. Polls in Ohio, where Mrs. Clinton has led, close 30 minutes later. Rhode Islanders will vote until 9 p.m. Eastern time.

Picking the president: The candidates Click to visit that candidate's MSNBC page or click the XML symbol for an RSS feed. John McCain                Barack Obama

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