The decision by the Senate's best-known independent to snub the Democratic Party could help McCain win a bigger share of the tide of independent voters who have been expected to flow to the Democratic field in New Hampshire's first-in-the-nation primary on Jan. 8.
Independents outnumber Republicans and Democrats here, and the state is key to McCain's hopes for the GOP nomination.
Support from a high-profile senator who almost always caucuses and votes with Democrats risks alienating conservative GOP voters, angry already at what they see as McCain's abandonment on immigration and campaign finance. Democratic leaders expressed their annoyance, too.
There was no doubt, however, about the Lieberman announcement's buzz effect - no small factor in a race now in the homestretch with a large field. The news injected energy and interest into the McCain campaign, still behind in the polls but glowing from a weekend of coveted newspaper endorsements: from The Des Moines Register in Iowa, where he is barely competing in the Jan. 3 caucuses, as well as from The Boston Globe and The Portsmouth Herald - both influential in New Hampshire. He'd already been endorsed by The New Hampshire Union Leader.
McCain also seemingly has enough money to stage a more serious play for South Carolina. He announced Monday he is going on the radio there with a spot featuring the state's popular Republican Sen. Lindsey Graham - another of his Senate colleagues.
McCain's strategy, pared down after financial and organizational troubles earlier this year, now calls for winning New Hampshire and using that boost to lay claim to South Carolina.
Independents, who can vote in either party's primary in New Hampshire, are the wild card. They helped McCain beat George W. Bush here in 2000. McCain advisers are hoping for a repeat - but this time not followed by a loss in South Carolina and defeat for the nomination.
On the first day of a two-day Straight Talk Express tour through New Hampshire - McCain's second bus tour of the state in two weeks, he said "I do" when asked if he senses upward momentum. His crowds are bigger and more enthusiastic, his Internet hits more frequent and his poll numbers are rising, McCain said.
"But I am not an unbiased observer," he said, adding some realism.
"We have a long way to go," McCain said, aware that opinion polls still show him trailing far behind fellow Republican Mitt Romney in New Hampshire.
Roberta Adams and George Merrill, both undecided voters who drove from nearby Antrim to check out McCain, came away impressed but uncommitted. Merrill, a registered Republican, said New Hampshire's independent spirit means the endorsement by Lieberman not only doesn't hurt McCain with Republicans but helps.
"We're not voting for the party, we're voting for the man," Merrill said.
McCain said the support from an "independent Democrat," as the Connecticut senator calls himself, will answer the people who invariably ask him in town hall meetings, "Why can't you all work together?"
Lieberman reinforced the message. He said he chose his longtime Senate colleague as the best candidate of either party because of his national security credentials and because McCain has the best shot of breaking through partisan gridlock.
"You may not agree with John McCain on everything - I don't," Lieberman told those gathered in the American Legion hall. "But you can always count on him to be honest with you about where he stands and to stand where he honestly thinks it's best for our country."
Lieberman said he had planned to wait until after the primaries to make a 2008 pick, but changed his mind when McCain called - the only candidate, including fellow Connecticut Sen. Chris Dodd who is running for president on the Democratic side, to do so.
Lieberman won re-election to the Senate in 2006 as an independent, after losing the Democratic primary to upstart Ned Lamont, largely because of Lieberman's support for the war.
Lamont said Monday, "It is now clear that Joe Lieberman is the one working to defeat our hopes."
Said Senate Majority Leader Harry Reid, D-Nev.: "I have the greatest respect for Joe, but I simply have to disagree with his decision to endorse Senator McCain."
In South Carolina, McCain backers had been growing restless as the campaign put most of its resources into TV ads in New Hampshire and all but planted the candidate there, save for a few days. Supporters pressed the campaign to send money south to show he hadn't abandoned the state. They apparently got their wish: A radio ad begins this week, focusing on McCain's position on Iraq and featuring Graham - an issue and a person close to the hearts of many South Carolina Republicans.
"I've been to Iraq nine times. The troop surge is working. Terrorists are on the run, and we need a president prepared to win," Graham says in the ad. "Only one candidate had the courage to call for the troop surge in spite of the polls, and that's John McCain."
