The three presidential candidates and much of the U.S. foreign policy establishment all favor presenting a “kinder, gentler” face to the world than President Bush’s, but both parties have opened big holes in their appeal.

[IMGCAP(1)]For the Democrats, it’s union-pandering opposition to free trade, which will deny foreigners access to U.S. markets — and vice versa — and wipe out the benefits of the big increases in foreign aid that they advocate.

Democratic Sens. Barack Obama (Ill.) and Hillary Rodham Clinton (N.Y.) are vying with each other to denounce the landmark North American Free Trade Agreement, a net boon to all countries involved, and Democrats in Congress are blocking the Colombia Free Trade Agreement despite it including labor and environmental standards.

Congressional Republicans, meanwhile, are mounting new efforts to embarrass Democrats — and their own nominee, Sen. John McCain (Ariz.) — with restrictive new measures on immigration. Ostensibly, they are just designed to block or drive out illegal immigrants, but the GOP has done nothing to alter the impression that all immigrants are unwelcome in America.

Iraq remains a major political burden for Sen. John McCain (R-Ariz.), with most polls showing that 60 percent of voters believe the war was a “mistake,” although polling also indicates increasing awareness that the McCain-backed “surge” is achieving results.

Almost daily, Obama and Clinton repeat the charge that McCain advocates a “100 year war” in Iraq — a canard that McCain should have taken steps to correct in his major foreign policy speech in Los Angeles on Wednesday.

What McCain actually said in a January town hall meeting in New Hampshire was that U.S. troops might be stationed in a peaceful Iraq for 100 years on the same no-casualty basis that they’ve been in Germany for 60 years and South Korea for 50.

It’s clear, though, that Iraq — and also Iran — will be major issues in the fall election, with Democrats promising to withdraw combat troops on a timetable and deal diplomatically with Iran, and McCain declaring that “abandonment” of Iraq would be “morally reprehensible” and sometimes threatening war to stop Iran’s nuclear program.

Beyond those two big issues, however, a broad consensus is developing that the U.S. needs to change its image and practice in the world by emphasizing diplomacy, development and multilateralism instead of concentrating on exercises of military power.

“Smart power” is the tag line being used by a number of establishment figures in both parties to describe the combination of aid, trade, exchanges and diplomacy needed to supplement, though not replace, America’s military might.

That’s the title of a report issued last year by a commission assembled by the Center for Strategic and International Studies chaired by former Deputy Secretary of State Richard Armitage and Harvard professor Joseph Nye, originator of the concept of “soft power” to describe America’s non-military assets in international affairs.

Armitage, formerly the top aide to Secretary of State Colin Powell, told Washington Diplomat newspaper that “we’ve been exporting fear and anger after 9/11, rather than the more traditional export of hope and optimism and opportunity. … The U.S. has to be involved across the full breadth of our foreign policy toolbox and not so heavily weighted toward the military.”

A similar message is being issued by the Center for U.S. Global Engagement and its Impact ’08 election-year effort, led by former Democratic Secretary of State Madeleine Albright and former GOP Defense Secretary Frank Carlucci and signed onto by an all-star cast of former top officials, plus 50 retired generals and admirals.

Two of the latter, former CENTCOM Cmdr. Gen. Anthony Zinni and retired Adm. Leighton Smith, testified before the Senate Foreign Relations Committee in March for increasing the U.S. international relations budget — especially for foreign aid and diplomats — declaring that “the U.S. cannot rely on military power alone to keep us safe from terrorism, infectious disease and other global threats that recognize no borders.”

Non-military “international affairs” spending rose to 0.5 percent of GDP in 1985, then fell to a low of 0.2 percent in 1997. It’s less than 0.3 percent now.

Emphasis on smart power is a recurrent theme for Obama and Clinton, of course, both of whom have promised major increases in funding for foreign aid and especially programs to combat HIV/AIDS and other diseases in the developing world.

But McCain, too, is sounding a tune different from the tough-guy talk from Bush, Vice President Dick Cheney and former Defense Secretary Donald Rumsfeld during Bush’s first term — and which still lingers in world opinion despite significant exercises in disease-fighting and diplomacy during Bush’s second term.

In Los Angeles, McCain reiterated his conviction that terrorism is “the central threat of our time” but also declared that “the United States cannot lead by virtue of its power alone. We must be strong politically, economically and militarily. But we must also lead by attracting others to our cause.”

In the struggle against terrorism, he said, “scholarships will be far more important than smart bombs.”

During his recent trip to Europe and in the L.A. speech, McCain obviously sought to distance himself from Bush by promising to negotiate “a successor to the Kyoto Treaty” on global warming. Bush’s outright rejection of Kyoto was a major contributor, along with Iraq, to the cratering of America’s world image.

McCain also hopes that his past advocacy of comprehensive immigration reform will distinguish him from Congressional Republicans, who this month proposed a bevy of new measures designed to catch and deport illegal immigrants and punish employers who hire them.

After the defeat of comprehensive reform last year, however, McCain switched to a “seal the borders first” stance on immigration and he absented himself when the Senate voted on budget amendments to, among other things, punish localities that refuse to allow their police to round up illegal immigrants.

A National Democratic Network review of 2008 exit polls indicated that 78 percent of Latino voters participated in Democratic primaries this year, further evidence of a steep falloff in Latino support from 2004, when Bush won 40 percent of the vote.

Anti-immigrant fever also has led Congress to ignore pleas — by Microsoft Chairman Bill Gates, among others — to increase visas for highly skilled workers and graduate students, sending a message to the world that the U.S. no longer is a welcoming place.

In the meantime, Democrats threaten to reverse free trade policies pioneered by presidents of their party, including Bill Clinton. The 1993 North American Free Trade Agreement, for example, tripled trade between the United States, Canada and Mexico and contributed to 58 percent growth in U.S. manufacturing output between 1993 and 2006.

Clinton has gone so far as to question whether the U.S. should pursue worldwide free trade agreements — a sure way to condemn poor countries to continued poverty. And rejection of the Colombia agreement would be a boon to Venezuelan President Hugo Chávez, a declared enemy of the United States.

The bottom line is that the candidates are talking a good new game in foreign policy. But in action, they are threatening to adopt policies as ugly as any advocated by Bush.