ST. PAUL, Minn. — Sen. John McCain on Thursday gets what one political scientist calls a Hubert H. Humphrey moment.
Forty years ago, Humphrey's ties to an unpopular president from his own party bogged down his presidential campaign. Late in that 1968 campaign, Humphrey removed his vice-presidential seal from his podium, a symbolic sign of his break from President Lyndon Johnson and the Vietnam War.
It started turning the tide his way — many said he'd have won if the election had been a week later — but it was too late.
On Thursday night, McCain gets his chance to show the country how he'd break with an unpopular president from his party, George W. Bush.
It's a tricky opportunity. Bush remains popular with many Republicans, but McCain also needs to appeal to independents who don't like Bush and who could be crucial in a close election. The Republican presidential candidate also needs to reach beyond them to the vast majority who think that the country is on the wrong track.
The key: reasserting his credentials as a maverick who's often willing to buck his party while also framing a fall campaign that challenges Sen. Barack Obama, the Democratic presidential nominee, over who could really change Washington.
"It's his Humphrey moment," said Dennis Goldford, a political science professor at Drake University in Iowa.
"McCain has to make the case that while he's a Republican, he's different. He's got to show what a McCain presidency would do differently from both the Democrats and the Bush administration."
Some of the points McCain is likely to make:
_ He broke with the Bush administration over Iraq, criticizing the strategy of Bush and former Defense Secretary Donald Rumsfeld at considerable political peril and pushed for the surge of additional troops that, along with other factors, has sharply reduced violence there.
_ He's been a vocal critic of pork-barrel spending — even by his own party.
_ He came out first in support of offshore oil drilling to ease U.S. reliance on foreign oil, prodding the White House to change its position.
He's also likely to stress that knows how to change Washington from the inside, a response to a line in Obama's acceptance speech last week that, "Change doesn't come from Washington, it comes to Washington."
Watch for McCain to remind viewers that he has a record of building bipartisan coalitions to reform the way politics or government works, such as the McCain-Feingold law regulating the flow of money to political campaigns and attempting to regulate what interest groups can say on television before an election.
"Everyone's for change this year," said Clark Judge, a former White House speechwriter for Ronald Reagan. "The question is, how do you change?"
While Obama promises to change an unpopular system of insider politics in Washington, Judge said, "McCain will say is that that's not enough, that you need somebody who's tough enough and mean enough to break it up."
Still, McCain will have the stage to himself for less than an hour.
Obama will hit back quickly with reminders, probably backed up by a new TV ad, that seek to reconnect McCain to Bush.
In a preview, Obama adviser Robert Gibbs on Wednesday stressed that Bush appeared via video the night before to endorse McCain, and that McCain wants to make the Bush tax cuts permanent and is closely allied with Bush's economic policies.
"President Bush enthusiastically passed the torch to the man who has voted with him 90 percent of the time and is promising to continue this president's legacy for the next four years," Gibbs said.
He also criticized McCain's running mate, Alaska Gov. Sarah Palin, saying that she supported the "bridge to nowhere" in Alaska before she turned against it, and that she hired a lobbyist to win federal earmarks for her small town when she was its mayor, the kind of spending that McCain criticizes.
"She doesn't have the record of reform that McCain says she does," Gibbs said. "McCain's selection of Governor Sarah Palin as his running mate shows that more of the same is exactly what John McCain is offering."
McCain heads into the speech as the underdog — he trailed Obama Wednesday 49 percent to 43 percent in the daily Gallup tracking poll — but with the impact of Palin's speech Wednesday night yet to be fully felt.
"The potential impact of the Palin and McCain speeches may not be seen until the weekend," said Gallup editor Frank Newport.
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