Senator Ted Cruz of Texas, the public face of the aimless and self-destructive Tea Party strategy to stop health care reform, began an endless floor speech on Tuesday with the theme of “make D.C. listen.” But even his Republican colleagues had long since stopped paying attention to his corrosive bombast, tired of his pious insults to his own party and unimpressed with his eagerness to shut down the government in pursuit of an ideological dream.

Like hard-liners in the far right corner of the House, Mr. Cruz has grabbed for every possible lever in his campaign against President Obama’s health law, fully aware that he will not succeed but eager for the accolades and donations that will inevitably follow from the Tea Party’s misguided faithful. In the process, he has demonstrated how little he understands Senate rules and, more important, how little he appreciates the public’s desire for a collaborative Congress.

Mr. Cruz’s campaign to defund health reform consists largely of an absurd plan to filibuster the very House bill that kept the government from closing and defunded the health law, a notion that was rejected by the Senate minority leader, Mitch McConnell, and most Senate Republicans. After he lost their support, he began an extended tirade anyway, a stunt that might resemble a filibuster but in fact will have to end Wednesday morning before a prescheduled vote on the House bill takes place.

In just the first hour of his speech, Mr. Cruz said his fellow senators were no more sincere than professional wrestlers and that accepting the health law was like appeasing the Nazis. His own goal of tearing down the law, he said, was a dream on par with President John F. Kennedy’s promise to put a man on the moon. This combination of grandiosity and pure nastiness helps explain why the senator has become the least popular man in Washington.