Donald Trump
Donald Trump could spell trouble for the GOP if he derails the party's attempt at message discipline. Above, Trump formally announces for the 2016 presidential nomination at Trump Tower in New York, Tuesday, June 16, 2015. Reuters/Brendan McDermid

WASHINGTON -- It could be a nightmare scenario for the Republican Party. In a presidential field now heading toward 20 participants, an unscripted, uncontrollable candidate starts to derail the party’s message -- and give Democrats a juicy target.

Donald Trump could deliver on that nightmare scenario. His hourlong announcement speech in New York Tuesday-- which seemed to follow no prepared text and meandered into myriad topics -- is the first, most glaring example.

Here are just a few of the questions that could come from Trump’s speech: Does Jeb Bush think the U.S. should build an impenetrable wall on the southern border and make Mexico pay for it? Does Marco Rubio think Mexican immigrants are mostly drug pushers and rapists? Would Scott Walker take a phone call from the CEOs of the nation’s biggest car manufacturers?

Trump already has a history of making the GOP establishment uncomfortable with what he's willing to say on television. He was one of the loudest "birthers" who demanded to see long-form copies of President Barack Obama's birth certificate. He accused Obama of being a secret Muslim. And he's taken some of the most hard-line positions against immigration, a topic Republicans are trying desperately to moderate to stop scaring off Hispanic voters.

These aren’t the sort of questions the Republicans want to be debating in the primaries. They would rather talk about economic growth and fighting ISIS. And to be sure, Trump talked about those issues as well. But he is shaping up to fire off a barrage of off-message statements that would become fair game to ask the rest of the Republican field.

You could almost sense the glee and sarcasm jumping from the page when the Democratic National Committee responded to the Trump announcement. It wasn’t the usual attack piece they’ve put together for other candidates. “Today, Donald Trump became the second major Republican candidate to announce for president in two days,” DNC press secretary Holly Shulman said in an immediate statement, equating Trump with Bush. “He adds some much-needed seriousness that has previously been lacking from the GOP field, and we look forward hearing more about his ideas for the nation."

Republicans -- mostly those with establishment ties -- on Twitter weren’t mincing the words as they described Trump.

Brendan Buck, the communications director for House Ways and Means Committee Chairman Paul Ryan, R-Wis., who was the vice presidential nominee in 2012:

“Trump's stage entrance will last longer than his campaign,” conservative Republican strategist Matt Mackowiak wrote on Twitter.

Trump also poses a big problem for the lesser-known candidates in the GOP field. They will be depending on media attention and debates to gain traction. With his personal wealth, which Trump said he’ll spend on the campaign, he has the potential to squeeze out second-tier hopefuls. As a flamboyant, endlessly self-promoting entertainment personality, he’s likely to attract more media attention, cutting into time the rest of the field will be vying for.

And a handful of polls that have been conducted, actually have Trump doing well enough to find himself in the top 10 candidates -- meaning he could push people like Carly Fiorina or Sen. Lindsey Graham, R-S.C., off the debate stage.