Every four years, party strategists, political junkies and, well, reporters ponder the question, some with dread and others with relish:

Is this the year we will finally see a brokered convention?

It has been nearly 70 years since there was a true nominating fight on the convention floor, with candidates nervously waiting for delegates to go through rounds of voting to pick the eventual candidate.

Since then, both parties have made rule changes for picking and counting delegates to avoid that situation, primarily because a nominee in a brokered convention very rarely goes on to win the general election.

Senator Bernie Sanders of Vermont is leading the Democratic delegate race so far, and seems poised to continue his successful primary run. But none of his six competitors appear willing to drop out and party leaders continue to fret about a Sanders candidacy, increasing apprehension about a suspenseful convention in Milwaukee, rather than the predictable media event Americans have grown used to.