What Is The "Stop Trump" Movement? Republicans & Democrats Alike Are Scrambling To Stop The Donald

The Indiana primary has become unexpectedly pivotal in the Republican primary race, and anti-Trumpers are scrambling to figure out how to block the real estate mogul from becoming the next Republican nominee for president. One of the driving forces behind this push to keep Trump out of office is the Stop Trump movement, which has been building for months in response to the candidate's growing popularity and increasing delegate count. It's a powerful movement that's been getting a lot of attention for its attempted influence over the Republican primary race, but what exactly is the Stop Trump movement?

In short: The Stop Trump movement is essentially a loosely organized coalition of groups dedicated to supporting Ted Cruz and ending Donald Trump's run at the presidency.

Political operatives have been working behind the scenes for the past several months to help Cruz's campaign, including donating millions to finance advertising in battleground states and boost his chances of winning. Groups such as the Club for Growth, Our Principles PAC and the Trusted Leadership PAC have been funding ads since way back in September, when the Club for Growth started running attack ads against Trump in Iowa. Although the movement has been under criticism and speculation of its efficacy almost since the very beginning, its funding helped Cruz win Wisconsin and is now trying to help him win in Indiana as well, all in the hopes that Trump can be stopped from taking the nomination.

However, the cause is in trouble now. According to Politico, sources inside the high-powered Super PACs that are some of Cruz's biggest allies in battleground states say that donors are growing wary of the recent string of losses plaguing the Cruz campaign. “If Cruz loses Indiana, many donors will take a step back and reassess what may happen in California,” Sean Noble, a Republican strategist with ties to some anti-Trump donors, told Politico.

Right now, that's exactly what it looks like will happen. Trump had a decisive lead in the polls before Tuesday, aided by a couple key endorsements from revered Indianans, basketball hero Bobby Knight and former Notre Dame football coach Lou Holtz. Cruz attempted to turn the tables on Tuesday morning by hurling brutal insults at Trump during a press conference, calling him a "braggadocios arrogant buffoon," "pathological liar," and "serial philanderer," among other names, but it's unclear what impact that will have on the election, if any. The tactic could swing voters if Cruz is lucky, but it seems likely that he will lose the Indiana primary, and therefore the support of the Stop Trump movement.

Trump can't reach the minimum 1,237 delegates until the California primary on June 7, but if Cruz takes the loss in Indiana and his donors pull out, there really is no stopping Trump. Although the movement attempted to find a path to victory for Cruz, his campaign will likely be unable to move forward if he suffers a loss in Indiana.