DENVER  — A two-headed creature is stalking the Democratic convention, getting kicked and pummeled at every turn. “Bush-McCain” is not a political ticket, but a hyphenated target that Democrats have invented from necessity.

It’s much easier, they’ve found, to ridicule an unpopular president who stayed stateside during the Vietnam War than it is to criticize a former prisoner of war seen by many as a likable maverick. By morphing the two, they can smack one and hurt the other.

That’s how Barack Obama’s allies are going at Republican John McCain this week, linking him so relentlessly to President Bush that you’d think Bush is the GOP nominee this fall.

In one of several slashing speeches Tuesday, Illinois Rep. Rahm Emanuel said “McCain” three times, “Bush-McCain” three times and “Bush” 10 times. His best zingers were aimed more at the president than McCain.

“George Bush has put the middle class in a hole,” he said, “and John McCain has a plan to keep digging that hole with George Bush’s shovel.” Noting that Bush inherited a budget surplus that turned into a deficit, he said: “Mr. President, we will be forever in your debt. ... You would think the one thing President Bush was good at was inheriting things.”

For weeks, Obama and his surrogates have cast the Illinois Democrat as an agent of change, and McCain as a continuation of Bush’s policies. In Denver this week, they’ve streamlined and amplified the claim into a nearly ceaseless soundtrack.

It comes as some Democrats, especially commentators linked to former President Clinton, are urging the convention planners to hit McCain harder. The Obama camp has opted for a middle ground: assail the unpopular president and nick McCain by proxy, avoiding the backlash that could result from frontally assaulting a 71-year-old former POW.

“You have to be careful about attacking McCain” because of his life story, Tennessee Gov. Phil Bredesen said Tuesday.

Chicago Mayor Richard Daley also urged caution. “I think America is sick and tired of everybody being negative,” he said.

But Democrats cannot let four days of televised attention pass without undercutting McCain as they build up Obama. Their strategy rests on a vital linchpin: Voters must believe that McCain will continue Bush’s policies on the economy, Iraq, domestic surveillance and other issues, which have proven unpopular with millions.

They cite a Congressional Quarterly study that found that McCain voted with Bush 90 percent of the time on legislation on which the president had a clear position since 2001. In 2007, he voted with Bush 95 percent of the time.

McCain has tried to blunt the message, seldom appearing with Bush these days, suggesting the president mishandled Russian leader Vladimir Putin and noting how he bucked the GOP establishment on matters such as campaign finance.

“We’re worse off than we were four years ago,” says a McCain TV ad, a stark criticism of the administration.

Still, six in 10 adults think McCain will follow Bush’s policies, according to an AP-Yahoo News poll in late June.

 “You can’t expect change from a senator who voted in lockstep with President Bush 95 percent of the time,” House Majority Leader Steny Hoyer, D-Md., told the crowd.

The night’s most important speaker, Sen. Hillary Rodham Clinton, delivered one of the sharpest jabs. “It makes sense that George Bush and John McCain will be together next week in the Twin Cities,” she said. “Because these days they’re awfully hard to tell apart.”

———

EDITOR’S NOTE — Charles Babington covers politics for The Associated Press.