Rep. Paul Ryan (R-Wis.) this week. (Carolyn Kaster/Associated Press)

INSTEAD OF adding his name to the already long list of people running for president, Vice President Biden pleaded Wednesday for something the country has in desperately short supply: functional, cooperative government. “I don’t think we should look at Republicans as our enemies,” Mr. Biden said. “For the sake of the country, we have to work together. . . . Four more years of this kind of pitched battle may be more than this country can take.”

Mr. Biden’s comments were an implicit criticism of Hillary Clinton, who offhandedly styled Republicans as her enemies during last week’s Democratic debate. But his message was double-edged: In order for Democrats to work with Republicans, Republicans have to be willing to cooperate. Even with Rep. Paul Ryan (R-Wis.) on the rise, the GOP still doesn’t appear to accept the realities of governing in a pluralistic democracy.

As Mr. Biden delivered his remarks Wednesday, Mr. Ryan was meeting with Republicans across Capitol Hill. The previous evening, he issued a demand: In return for accepting the top job in the House, Mr. Ryan insisted he get widespread support in the GOP caucus and that lawmakers agree to a rules change making it harder to oust the speaker. “It is our duty to make the tough decisions this country needs to get back on track,” he said, promising “results.”

Yet Mr. Ryan didn’t tell his caucus what he would really need from it to make the tough decisions the country requires. The nation faces national default and disgrace next month if Congress fails to raise the debt limit. Even if Speaker John A. Boehner (R-Ohio) forced through an increase before Mr. Ryan took over, the issue would come up again. Mr. Ryan did not mention this crucial issue, even obliquely. Nor did he mention the ruinously foolish budget caps that have shortchanged defense and domestic spending, nor the seemingly constant threat of government shutdown over hot-button side issues.

Whoever leads the GOP in Congress must be clear: Republicans can nudge the country in the direction they want to go, but they can’t drag it kicking and screaming. If a legislative deal leans 60 percent in the GOP’s direction and avoids the threat of default or shutdown, that is a Republican victory. Declining to take the country’s full faith and credit hostage is not weakness, it is wisdom. Toughness means taking votes that the bloviators on talk radio will not like, not just those that pass a conservative purity test.

Mr. Ryan has shown he appreciates these points. As elements of the perpetually outraged right wing have pointed out, he voted for the Troubled Asset Relief Program when the economy depended on it. He worked with Sen. Patty Murray (D-Wash.) to craft a compromise budget that, while deeply imperfect, gave the country a rest from near-constant budget acrimony. Though his position isn’t crystal clear, he has supported the sort of comprehensive immigration reform that most Americans favor and that the country requires.

“It’s not too late to save the American idea,” Mr. Ryan said Tuesday, “but we are running out of time.” As much as anything else, the American idea is that a religiously, ethnically, ideologically diverse group of people can govern themselves through common allegiance to a political system that requires compromise. A powerful bloc in Congress’s majority party refuses to accept this idea, and the fuse on national default is burning low. If Mr. Ryan is to be an effective speaker, he must be clearer about what true GOP leadership would look like.