Conservative intellectuals used to quote Richard Weaver's maxim that ideas have consequences. But as the modern GOP is demonstrating, the absence of ideas has consequences, too.

President Trump's rhetorical assault on Baltimore — and the GOP pile-on that followed — is the most recent example of the right's intellectual destitution. Conservatives are out of real ideas — and, in some cases, disdainful of them — and are compensating with catchphrases and vitriol.

Trump this week described Baltimore as "a disgusting, rat and rodent infested mess." The city, he said, has "been very badly mishandled for many years" and "has the worst Crime Statistics in the Nation." On Monday, Trump tweeted some more: "Billions of dollars have been pumped in over the years, but to no avail. The money was stolen or wasted." He continued to escalate his attacks through the week.

Trump is attacking Baltimore for the same reason he used to attack Chicago: because someone he doesn't like is from there. In this case, it's Rep. Elijah Cummings (D-Md.), who, as chairman of the House Committee on Oversight and Reform, vexes the president by overseeing the executive branch and, perhaps also, simply by being African American.

Republicans, not knowing what to say, have so far said almost nothing. Either they have defended the president, or they've tried to redirect the conversation toward "policy." "This town ought to be about policy," Sen. Chuck Grassley (R-Iowa) said. Sen. Lamar Alexander (R-Tenn.) added: "I like Baltimore and I like it better when the president talks about policy."

But there's a problem: The president is unable to talk about policy in a constructive way. When Trump talks about health care, for instance, he says things like this: " I know a lot about health care ." Thanks to Trump, Republicans aren't adept at policy talk, either. That's because they no longer know what they stand for: free trade or tariffs? A strong NATO or its abolition? Family values or adultery?

Without a positive vision of their own to articulate, conservatives are assailing their opponents, instead. On Monday, Sen. Steve Daines (R-Mont.) introduced a resolution to condemn socialism. "A radical, socialist, far-left movement is growing across this country. And it has taken root as the new voice of the Democratic Party," Daines said

Democrats, of course, are guilty of taking shots at their foes, as well. But Trump and his defenders are particularly melodramatic and categorical in castigating their opponents. Paradoxically, the less they have to fight for — and the fewer constructive policy ideas they have to offer voters — the more vitriolically they fight. At a recent event, Trump again lambasted four Democratic congresswomen of color, known as "the Squad," calling them "left-wing ideologues" who see America as "a force for evil."

As an intellectual movement, conservatism was bankrupt before Trump's nomination. The Heritage Foundation had become an activist group for the Republican Party, which had nominated Sarah Palin for vice president and flirted with Herman Cain a few years later. Instead of William F. Buckley Jr., conservatives had Fox News and Rush Limbaugh. In September 2015, Rush Limbaugh questioned the value of "conservative principles" as such. "I, for one, am tired of conservatism being nothing more than some intellectual feast every day," he said.

But Trump's presidency has exacerbated the problem. In the 2016 GOP primary, the candidates debated an array of ridiculous non-issues, such as the possible involvement of Ted Cruz's father in the assassination of John F. Kennedy, and the size of Trump's hands and other appendages.

Reagan gave the party optimism and ideas — supply-side economics, the Strategic Defense Initiative, etc. Trump gave it hyperbole and incoherence because he had nothing else. Instead of talking about a shining city on a hill, Trump at the time talked about cities whose factories had closed and whose streets were overrun by drug-dealing rapists from Mexico. His appeal was ethno-nationalist, not strictly ideological. He offered no specific solutions to America's problems, only a vague promise to fix all of them by himself.

Now, similarly, his only advice about how to improve Baltimore is for Cummings to "investigate himself." His position on Somali refugees is equally hazy: "Get smart people! #MAGA." As the president recently advised, "IF YOU ARE NOT HAPPY HERE, YOU CAN LEAVE!"

This is not a real solution to any problem. In the absence of any actual ideas about improving America's cities or immigration policy or health care, Trump is blustering and braying to rile up voters. And Republican legislators are following his lead. In an interview with Breitbart last week, Sen. Rand Paul (R-Ky.) said he would buy Rep. Ilhan Omar (D-Minn.) a plane ticket to Somalia to make her "appreciate America more."

Republicans say they love America, but they detest half of it. The GOP used to be the party of ideas. Now it's the party of smears and slogans.