Does Donald Trump's appeal have anything to do with his policy positions? ABC analyst Matthew Dowd says it doesn't — Trump's rise, he argues, is all personality, no policy:

@danpfeiffer @ezraklein @jbarro trump's voter support has nothing to do with any issues. it has to do with gut and bravado. — Matthew Dowd (@matthewjdowd) August 15, 2015

This is, for Republicans, the more comforting interpretation of Trump's emergence — he's a candidate powered by a potent mix of celebrity, outrage, and chutzpah, but he's not really a Republican, and as the primary grinds on, Republican voters will figure that out.

But there's another possible interpretation — this one more worrying for Republicans. In this interpretation, part of what makes Trump dangerous is that he's willing to cater to the opinions of the Republican base in ways that the Republican establishment wouldn't dare. And in doing so, he can exploit longstanding cleavages between the Republican Party and the voters it represents.

Republicans agree with Trump on immigration

So far, Trump is known for one policy position: He will deport unauthorized immigrants. And, more broadly than that, he's known for one policy idea: that immigration, and particularly illegal immigration, is hurting American workers.

And sure enough, a recent CBS News poll found that Trump leads the field when you ask Republican voters whom they trust most on immigration. That's not true on all policy issues, by the way — Trump badly lags Jeb Bush when you ask about dealing with America's foreign adversaries.

But when it comes to immigration — the one policy question on which everyone knows Trump's stance — Republican voters prefer him to the other candidates.

And it goes beyond just immigration. The first Republican debate was designed to show Republicans that they disagreed with Trump on all sorts of issues — he was called out on his disloyalty to the Republican Party, on his past support for single-payer, his treatment of women, his donations to Democratic candidates, and his past support for abortion. And at one point in the debate Trump, without being asked, volunteered that he believed the Iraq War was a mistake. The result?

As Greg Sargent wrote, "The possibility that plenty of Republicans simply agree with [Trump's] specific pronouncements and positions, such as they are, should at least be entertained."

At least.

Republican voters don't want entitlement cuts. Republican elites do.

The broader issue here is that both parties are, at best, imperfect reflections of their bases. There are, for instance, pro-life Democratic voters — but you wouldn't know it watching congressional Democrats legislate. Similarly, there are Republicans who believe in taxing the rich and spending much more on programs for the poor, but those beliefs aren't reflected by the day-to-day actions of their elected representatives.

The gap between the rigid agendas followed by the party establishments and the more diverse opinions of loyal partisans leaves both parties vulnerable to a candidate like Trump who has the money, and the star power, to campaign on a platform that party elites would normally suppress.

Take spending cuts. It's table stakes in a Republican primary to talk about how you'll cut spending on Social Security and Medicare. The GOP's policy apparatus loathes both programs and considers their long-term cost to be among the most pressing economic threats facing the nation. Any Republican candidate who wants to be taken seriously by Republican Party elites needs to show they understand the urgency of cutting Social Security and Medicare spending.

One problem? Republican voters don't understand the urgency of cutting entitlement spending. In fact, they oppose cutting entitlement spending. More Republicans want to increase spending on Social Security and Medicare than decrease it. They think keeping entitlement benefits at current levels is more important than reducing the deficit.

This puts Republican voters at odds with the Republican establishment and conservative interest groups. But since Republican candidates can't get very far without some level of support from the GOP establishment, conservative interest groups, or both, the Republican Party's elected officials are basically united on cutting Social Security and Medicare, even though Republican voters hold the opposite view.

Trump is the only Republican running who actually agrees with the GOP base on this one. "They're gonna cut Social Security. They're gonna cut Medicare. They're gonna cut Medicaid," he said on Fox & Friends. "I'm the one saying that's saying I'm not gonna do that!"

And that's what makes a candidate like Trump potentially dangerous. On immigration, Trump holds a hard-line position that the Republican Party establishment has tried to mute, and so far Republican voters are loving it. On Social Security and Medicare, Trump — who opposes cuts — is closer to Republican voters than the party establishment is. On free trade deals, Trump shares a skepticism held by about half of Republican voters, but that's usually suppressed by the party's powerful business wing.

Most candidates who tried to stack this many heterodoxies would be quickly squelched by the party establishment. But Trump isn't beholden to the GOP for money, staff, power, or press attention. That frees him to take positions that Republican voters like but Republican Party elites loathe.

It may be true that support for Trump, so far, is about personality rather than policy. But as the primary wears on, Republican voters might find that they actually agree with him. And that's going to put the rest of the Republican field — all those candidates who were playing by the establishment's rules — in a very tough position.

Correction: This post originally identified Dowd as a Republican political consultant. Dowd, who previously advised George W. Bush and the Republican National Committee, clarified that he's no longer a political consultant, and he now identifies as an independent. The text has been updated.

VIDEO: Donald Trump on immigration