Donald Trump's sweep of the Indiana primary proves beyond a doubt he will be the Republican presidential candidate.

On Tuesday night in Indianapolis, Ted Cruz threw in the towel and signaled the end of a doomed effort to derail Trump.

Establishment Republicans, in particular the neocon faction, have flirted with the idea of launching a third party to oppose Trump. It's far too late for that, however.

Advocates are up against the clock and will be hard pressed to collect millions of dollars needed to get the party rolling. Many states have complex rules and deadlines for third-party candidates. Collecting the required number of signatures to get third party candidates on general election ballots will be a herculean task.