By Rachel Kapochunas, CQ Staff

Republican Sen. John McCain of Arizona captured a key primary win in Wisconsin on Tuesday, bringing him a big step closer to securing the GOP presidential nomination — and to what McCain suggested will be a general election contest against Illinois Sen. Barack Obama , whose own Wisconsin win Tuesday was his ninth consecutive primary or caucus victory over New York Sen. Hillary Rodham Clinton .

McCain defeated his remaining major rival, former Arkansas Gov. Mike Huckabee , by 55 percent to 37 percent. Texas Rep. Ron Paul , the libertarian iconoclast who is the only other active candidate still in the race, had 5 percent.

Wisconsin will send 40 delegates to the Republican National Convention this September. Of that number, 24 district-level delegates will be divided proportionally while 13 at-large delegates will all go to McCain. The other three delegates are RNC members. An Associated Press tally put McCain at 821 delegates to Huckabee’s 241 going into Tuesday night, and McCain must claim 1,191 delegates to lock up the nomination.

Later on Tuesday, McCain reinforced his advantage by claiming victory in Washington state’s primary, also held that day. With 57 percent of the vote counted, McCain had 49 percent of the Washington vote, while Huckabee ran a distant second with 22 percent — just barely ahead of (20 percent) former Massachusetts Gov. Mitt Romney , who quit the race after the Super Tuesday contests held Feb. 5. The candidates will divvy up another 19 delegates based on the primary results, with 18 previously determined by caucuses held Feb. 9 in which McCain defeated Huckabee by a much smaller margin.

McCain claimed victory in the Wisconsin primary — and expressed certitude about winning the Republican nomination — while speaking to supporters Tuesday night in Columbus, Ohio, in advance of that state’s March 4 primary.

And while McCain did not mention Obama by name, he made it clear he was juxtaposing himself against Obama as the possible Democratic nominee.

“I will fight every moment of every day in this campaign to make sure Americans are not deceived by an eloquent but empty call for change that promises no more than a holiday from history,” said McCain in an obvious reference to Obama’s campaign theme of political change. The remark got a loud ovation from McCain’s partisan crowd.

McCain, a former Vietnam War POW who has focused heavily on military-related issues during a quarter-century in Congress, insinuated that Obama, as a first-term senator, was too inexperienced to handle the foreign policy challenges that come with being president. McCain said Obama had threatened to bomb the U.S.-allied nation of Pakistan — a reference to Obama’s comment last year that he would consider unilateral military action in that nation’s territory if al Qaeda terrorist leaders could be located there — but McCain added Obama would be willing to negotiate with Iran, a nation with a hostile relationship with the United States.

McCain did refer to the economy, cited as a top priority by exit poll respondents in both parties’ primaries in Wisconsin. McCain said he would balance the federal budget through economic growth and repeated his oft-stated pledge to cut wasteful government spending.

But McCain — who stood out in the once-crowded Republican primary field for his early and consistent support for President Bush’s “troop surge” strategy in Iraq — returned to his defense and foreign policy credentials.

McCain spoke of winning the war against “Islamic extremists,” adding, “I know what our military can do, what it can do better and what it should not do . . . I know how the world works, I know the good and evil in it.”

During his speech, McCain gave a word of praise to Huckabee for his determination and said he has grown to admire his most persistent GOP opponent.

Early readings of details from the Wisconsin exit polls hinted that McCain was going to claim a rather easy victory. Most striking was that he and Huckabee split the support of self-described conservatives. This suggests McCain is still dealing with some skeptics on the right because of some policy disagreements and his overt efforts to position himself as a Republican maverick. But Huckabee — an ordained Southern Baptist minister whose strongest support base is among conservative evangelical Christians — would have needed to dominate among conservative voters to win the state, as McCain pulled typical strong support among less conservative primary voters.

Huckabee has insisted he remains committed to the race, arguing that he owes Republican voters a choice when they hold upcoming nominating contests, though he also concedes it will take a “miracle” for him to win the GOP nomination.

Huckabee’s campaign made Wisconsin a priority. He campaigned in the state Sunday and Monday, holding events in Milwaukee, Hudson, Eau Claire, and Appleton. He heads to Texas on Feb. 20 and 21 to campaign for that state’s March 4 primary. Along with Texas and Ohio, Rhode Island and Vermont will hold primaries on that date.

CQ Politics’ Grigs Crawford contributed to this story.