House Speaker Paul D. Ryan attempted to lift the horizons of his party with a speech last week in which he called for a competition of ideas rather than insults, and constructive political debate rather than the politics of demonization.

Ryan’s speech was aimed at pulling the Republican Party away from Donald Trump’s embrace — though he never actually mentioned Trump by name. Events quickly showed what he is up against. The speaker was quickly drowned out by a snarling argument between Trump and Sen. Ted Cruz of Texas over their wives that almost eclipsed the terrorist attacks in Brussels in the U.S. media.

By week’s end, the Republican race had gone into the gutter over tabloid charges of infidelity, which the senator vehemently denied and for which he blamed the New York billionaire, who called it unfounded. A race that seemed already at the bottom managed to find another low.

Ryan’s speech was a relatively high-minded moment in the middle of this mud fight of a Republican nominating contest. His effort to rescue the party from a coming crisis is laudable, but the root causes of the condition go far beyond Trump.

Republican presidential candidate Ted Cruz is blasting rival Donald Trump for a National Enquirer story accusing Cruz of having five mistresses. Here's a breakdown of how a week of fighting got us here. (Sarah Parnass/The Washington Post)

The front-runner for the nomination of the Republican Party is as much a reflection of the condition as a cause, a reality that Ryan (R-Wis.) touched on only lightly in calling for a more positive and uplifting approach to politics by all sides. Which means stopping Trump alone won’t necessarily solve all of the party’s problems.

Four years ago, scholars Thomas Mann, then with the Brookings Institution, and Norman Ornstein, then and now with the American Enterprise Institute, published a book examining the breakdown in American politics. It was titled “It’s Even Worse Than It Looks.”

The authors took aim at the gridlocked and dysfunctional politics of Washington and the broader issue of political polarization that has become endemic in recent years. They were unsparing but not even-handed in their critique. They were ahead of others in describing the underlying causes of polarization as asymmetrical, with the Republican Party — in particular its most hard-line faction — as deserving of far more of the blame for the breakdown in governing.

Mann and Ornstein are back again with a second and updated paperback edition, called “It’s Even Worse Than It Was.” The paperback arrives in the middle of the most raucous presidential campaign in memory, one that has exposed even more the fissures, fractures and divisions within the Republican Party coalition.

What played out primarily in the party’s congressional wing has come to consume the presidential nominating contest. In their own ways, Trump and Cruz have brought to the surface the economic and cultural anger among many of those in the party’s base as well as the distrust of the party leadership — the same motivating forces behind the Freedom Caucus rebels in the House Republican conference.

The current campaign only adds fuel to the Mann-Ornstein thesis of a Republican Party at war with itself in ways that have helped cripple the governing process. Trump and Cruz reflect the yearning within the Republican base for anti-establishment outsiders to topple the insiders in Washington.

Donald and Melania Trump and Heidi and Ted Cruz. (FROM LEFT TO RIGHT: AP Photo/Carlos OsorioJim Watson/AFP/Getty Images)

Ohio Gov. John Kasich, the third remaining candidate for the nomination, is a dissenting voice, calling for cooperation and compromise. At this point, he is not just a dissenting voice; he is a minority voice in the presidential competition, unless he can start winning more primaries.

Trump and Ryan represent bookends in a political debate that has considerable consequences for the Republican Party and for the country. Trump’s position as front-runner not only highlights the degree to which the party is being taken over by anti-establishment forces but also foreshadows the possibility of a significant defeat in November if, as the GOP nominee, Trump is unable to reverse his standing among women, Hispanics, African Americans and other voting groups.

Ryan represents something far different, politics grounded in ideas and policies and an attitude of goodwill toward the opposition that he inherited from his mentor, Jack Kemp, the former House member from Buffalo who prodded his party to be more open and inclusive.

Yet Ryan’s speech left unanswered key questions about his capacity to change the behavior of his party’s conference in the House and in particular the degree to which he is willing to find a governing coalition apart from the hard-liners in the Freedom Caucus.

As the country’s highest-ranking Republican elected official, Ryan symbolizes the establishment’s backlash to Trump’s candidacy, a backlash that has so far failed to stop the New York businessman’s march to the nomination. The resistance might yet succeed. Whether it does or doesn’t, it raises the question of whether this presidential campaign ultimately will produce a true course change for the party or merely end up intensifying the forces that have brought it to this moment.

I put that question to Ornstein in an email exchange Friday: “This really is, I believe, an existential crisis for the Republican Party,” he wrote. “Will it be a Ryan-style conservative, problem-solving party, or will it be either a Trump-style, authoritarian, nativist and protectionist party, or a Cruz-style radical anti-government party content with blowing things up as they now stand? Or, just as possible, will the party break apart, with no clue as to what will replace it or how the pieces will fit into the broader political system?”

The prospects for a crackup are real, given what Trump’s candidacy has revealed about the party’s fractured coalition. Trump’s views on issues, outlined on the campaign trail and in a recent interview with The Washington Post editorial board, represent a fundamental break with many of the conservative ideas that have been at the party’s core for years.

Trump’s constituency finds his support for protecting rather than transforming Social Security and Medicare appealing. His words of praise for the work of Planned Parenthood, apart from performing abortions, are anathema to many religious conservatives. His views on trade run counter to the free-trade philosophy of the GOP elites. His comments about reevaluating the U.S. role in NATO shocked many in the Republican foreign-policy establishment.

That’s the threat Ryan and others in the party see as they watch the nominating contest move into the next rounds of primaries. But it isn’t clear that what the speaker advocated in his speech would be enough to put the Republican Party in a better place, even absent Trump. House Republicans are still an unruly group and, with some exceptions, the GOP still prefers to try to do business with itself.

The Republican Party remains a party of protest. It continues to struggle to demonstrate that, on the national level, it can be a true governing party.