(Robert F. Bukaty/AP Photo)

Ron Paul's delegate insurgency has come to an end.

Supporters of the libertarian GOP presidential candidate fell short at the Nebraska GOP convention, where they had hoped to out-organize Mitt Romney's delegates and push Paul over a critical threshold that would have ensured him an official presence and speaking slot at the Republican National Convention in Tampa, Fla., in August.

As the last state where Republicans will hold a convention in which delegates are up for grabs, Nebraska represented the last chance for Paul's supporters.

Instead, Nebraska Republicans elected a slate of Mitt Romney delegates to represent the state in Tampa. Paul's supporters won only two of Nebraska's 35 national delegates, according to Laura Ebke, who leads the Nebraska chapter of the Republican Liberty Caucus and who has led Paul supporters' effort to win delegates in the state.

Along with delegates from Iowa, Louisiana, Maine, and Minnesota, Nebraska could have given Paul the support of a plurality of delegates in five states; according to Republican National Committee rules, Paul would have been officially eligible as a candidate for the nomination at the Tampa convention. Organizers would be required to grant Paul's faction up to 15 minutes for a nominating speech.

To some extent, the outcome had already been determined: The voting attendees of Nebraska's state convention were selected in a two-party county-convention process that included registration on March 1 and voting events June 1-10.

Now, Paul is guaranteed nothing in Tampa, and will depend on the graces of Romney and convention organizers to include him in the proceedings in late August. In 2008, Paul was shut out of the Republican National Convention in Minneapolis and held his own event across town, as Republicans rallied around their new presidential nominee, John McCain.

Paul's campaign has said it expects to bring as many as 500 supportive delegates to Tampa, so Paul's presence there could be noticeable nonetheless. Paul is planning a rally in Tampa around the convention, and his supporters have organized Ron Paul Festival, an independent event that will include live music.

The Nebraska convention marks the end of Paul's insurgent, delegate-driven campaign, which saw his supporters out-organize mainstream Republicans and longtime local party participants at caucuses and conventions in a few states, sometimes leading to heated exchanges and physical confrontations with security or police.

Throughout the primary and caucus season, Paul supporters used technical knowledge of GOP procedures, posing parliamentary questions and attempting to wrest control of organized party meetings. On the whole, they were successful in some cases - but not enough to force their candidate into the GOP's multi-day Tampa love-fest.