McCain Secures GOP Nomination

(CBS/AP) CBS News projects Republican Sen. John McCain has clinched the Republican nomination for president following wins in Texas, Ohio, Rhode Island and Vermont on Tuesday.

"I am very pleased to note that tonight, my friends, we have won enough delegates to claim with confidence, humility and a sense of great responsibility that I will be the Republican nominee for President of the United States," McCain told supporters in Dallas, Texas Tuesday night, according to his prepared remarks.

McCain's last Republican rival, Mike Huckabee, dropped out of the race after the results came in.

"What a journey," Huckabee told supporters in Texas Tuesday night. "A journey of a lifetime."

President Bush will endorse McCain on Wednesday. McCain will travel to the White House to receive the endorsement and have lunch with the president.

CBS News reports that Democratic presidential contenders Barack Obama and Hillary Clinton both called the Arizona senator Tuesday night.

"This clears the path for McCain to begin his general election process in earnest," said CBSNews.com Senior Political Editor Vaughn Ververs. "With a possible protracted battle on the Democratic side that could continue for weeks, it's a luxury Republicans need as they enter into a difficult road towards November."

In remarks Tuesday night, McCain said "we begin the most important part of our campaign," now that he's wrapped up the Republican presidential nomination.

McCain and his wife appeared at a rally in Dallas where a big sign bearing number 1,191 was on prominent display. CBS News estimates that McCain secured 1,199 delegates with Tuesday's wins; 1,191 are necessary to clinch the GOP nomination. (Click here for latest tally.)

The Arizona senator expressed gratefulness to the broad support he's received, not only from Republicans, but independents and as he put it, "independent-thinking Democrats."

He also took a few moments to praise Huckabee, calling the former Arkansas governor a "great, fine, decent American."

McCain said his campaign will make a "respectful, determined and convincing case to the American people" that his election as president is in the best interest of the country.

Tuesday's triumph comes in McCain's second run at the nomination, after his loss to Mr. Bush in 2000. Once the front-runner for 2008, his campaign nearly imploded last summer. But he regrouped, reassuming the underdog role that he relishes, and methodically dispatched one rival after another in a string of primaries in January and early February.

Huckabee told supporters Tuesday that McCain "has run an honorable campaign because he is an honorable man."

The Baptist minister and former Arkansas governor won the GOP contests in Alabama, Arkansas, Georgia, Tennessee, West Virginia, Louisiana and Kansas in addition to the Iowa caucuses. He had come under increasing pressure from Republican leaders to drop out of the race after McCain emerged as the likely Republican nominee after Super Tuesday.

"We aren't going away completely," said Huckabee, who campaigned on a social conservative platform. "We want to be a part of helping to keep the issues alive that have kept us in this race."

Updated by LS

The Associated Press and CBS News contributed to this report.