Caucuses are indefensibly awful ways in which to select delegates to a political party’s national convention, and they are an even worse way in which to sort out the field of candidates for either party’s nomination.

Why?

Caucuses are time-consuming and complicated endeavors that are designed to repel rather than attract participation. Those who do so engage in a public setting that is ripe with opportunities for intimidation.

Perhaps worst of all, caucuses can be “gamed” by campaigns and powerful interest groups. For instance, the location of a caucus site can decide whether working people can participate — as the whole fight over whether Nevada caucuses will be held in Las Vegas casinos illustrates. And the gaming creates an inherently unequal process. Casino workers have the caucus brought to them, while cab drivers must take a busy Saturday off in able to play their part.

Going into Saturday’s Nevada caucuses, the balance is tipped in favor of Barack Obama. He has the backing of the biggest union in the state, the Culinary Workers, and that union has successfully defended a system that makes it easier for its members to participate in the caucuses than other Nevadans. (In fairness to the Culinary Workers, they have not done anything wrong — in fact, they have explored a smart new route for increasing political participation by allowing voting at the workplace. And they have did so with the enthusiastic support of all the major Democratic candidates — until the point at which they endorsed Obama and allies of Hillary Clinton began to object.)

Obama also has the endorsements of several of the state’s major daily newspapers, including the Las Vegas Review-Journal and the Reno Gazette-Journal (which bluntly declares that the Illinois senator “embodies the political and ideological perspectives that the party projects”) and of key political players such as state Senator Steven Horsford.

Obama’s spent an immense amount of time in Nevada, working the state as it has never been worked before. His campaign and its supporters have spent a fortune on television and radio advertising in the state, and the thrust has been far more aggressive than in previous contests. Ads attacking Clinton are all over the radio. A Spanish-language commercial, paid for by UNITE-HERE, the parent union of the Culinary Workers local in Las Vegas, translates as, “Hillary Clinton does not respect our people. Hillary Clinton supporters went to court to prevent working people from voting this Saturday — that is an embarrassment.”

Put the pieces together and this points to an Obama win. No one benefits so much as Obama from the structure of the caucuses in Nevada, and he and his supporters have worked that structure from all the angles. They have, at the same time, attracted the sort of mainstream support and favorable media coverage that is traditionally afforded a front-runner.

And what if Obama loses? It’ll be a serious setback after a week that, without a win, is likely to be remembered not as a time of triumph but as a moment in which he failed to capitalize on tremendous advantages — and in which the Democratic senator praised Republican-icon Ronald Reagan for addressing “the excesses of the 60s and 70s.” Of course, Obama will remain in the race, but his momentum will stall at precisely the time when he keep advancing against Clinton forcs that are ever on the watch for signs of vulnerability and weakness in their opponents.

Bottom line: While caucuses should not be definitional, this one could be. Nevada has become a must-win state for Barack Obama. He should get that win; but if he doesn’t it will be a stumble for the campaign that played Vegas with the best hand.