On Senator Brownback I had pretty much given up hope. In pursuit of his party’s nomination for president, the Kansas Republican had been searching for bipartisan exit strategies from Iraq. He favored the diplomatic surge recommended by the study group headed by Secretary Baker and the Democrat Lee Hamilton, but he opposed the military one favored by his president, the leader of his own party.

When asked last month why he was voting for a nonbinding bipartisan resolution opposing the surge, he said he was in favor of a “political solution,” whereby Iraq was divided into three ethnic provinces under a loose federal government. He had spoken with Iraqi leaders and General Petraeus, who, at least when he headed Fort Leavenworth in Mr. Brownback’s home state, had never told the senator that he favored more soldiers. The general commanding the rescue of Baghdad, the senator seemed to be suggesting, was against it before he was for it.

So is Mr. Brownback. “We can express opposition to the surge, which I certainly have done,” the senator said Thursday during the debate over Senator Reid’s bill to mandate a timetable for withdrawal from the field. “But after doing so I think we should oversee the implementation of it, not try to undercut it, nor should we attempt to undercut a mission just getting underway.” In prose Vice President Cheney might use, he said the Reid resolution, which lost 50 to 48, played directly into the hands of Al Qaeda. Today, the senator’s campaign Web site says the situation in Iraq is “precarious, but hopeful.”

So what happened? One reason Mr. Brownback migrated back to supporting the president is that the Democrats stopped trying to woo him. The withdrawal timetable put forward by Mr. Reid was right out of Jack Murtha’s strategy to stop the war. It was unacceptable to GOP fence sitters except for Senator Smith of Oregon. Mr. Brownback is a man who could be expected to be a favorite of the Republican Party’s religious base. He is a religious Christian who actually defended General Pace’s comments that homosexual acts are immoral. Yet Mr. Brownback was finding his appeal to the base lacking.

Mr. Brownback was a member of what syndicated talk-radio show host, Mark Levin, a former chief of staff to Attorney General Meese, called the “repubics,” meaning Republicans willing to vote with the Democrats against victory in Iraq. Hugh Hewitt, another talker who became so exercised about those in his party back-pedaling on the war that he asked fellow bloggers and listeners to sign a pledge to withhold support for any lawmaker supporting the anti-surge resolutions, worried about Mr. Brownback’s presidential bid.

“He has been trying to build his campaign on the idea of protecting human life from womb to death, and across the globe. That agenda cannot advance by retreating from the field on which the most pivotal of the current battles is being waged,” he wrote on January 31. Three days before, Mr. Brownback had brushed off critics who said he was playing into Al Qaeda’s hands. “I don’t see this enemy as needing any more emboldening or getting it from any resolution,” he told Christopher Wallace on Fox News Sunday.

In other words, Messrs. Hewitt and Levin, along with such figures as Sean Hannity, Rush Limbaugh, and Michael Reagan, are defining the base. While taxes, immigration, and values are important, this year the war trumps all. The people who will show up in New Hampshire and Iowa to pick the Republican nominee are victory voters.

Hence for all of their flaws, the big three contenders for the Republican prize talk about winning in Iraq. Mayor Giuliani may be too left on the social issues. Senator McCain may be too much of a lick-spittle to the liberal press. Governor Romney may be too new to the struggle. But none of the three wants to sabotage the mission the way the liberal Democrats do. It was Mr. Brownback who sputtered on the war, and when it became clear that it was not a winning course, he made a course correction.

Mr. Brownback had long advocated foreign policy in the spirit of one of his heroes, William Wilberforce, the 18th-and 19th-century British clergyman and lawmaker who helped found the first abolitionist movement. The senator was railing against the government in Sudan long before it sent the first marauders to slaughter people in Darfur. Few of his colleagues matched his commitment to exposing the gulags of North Korea. On Iran, only the former senator, Rick Santorum, was willing to take on the Bush administration as often and publicly as Mr. Brownback on behalf of their jailed liberals.

What happened last week is that the senator abandoned his flirtation with the notion that a retreat from Baghdad would spur Iraqi leaders who had encouraged the city’s ethnic cleansing to seek the political solution. On the floor of the Senate when it counted, he conceded that Iraq’s reconciliation is impossible without a military presence to counter the sectarian murderers. Wrapping up his floor speech against the Reid resolution, Mr. Brownback said, “I believe victory is still possible and that failure is unacceptable.”

It’s good to have him back.