The Democrats seem determined to teach us the price of vacillation, while the Republicans are bent on instructing us on the rewards of obstruction. What a helluva choice awaits in the November election.

This is my sour August reflection on the two months of travel ahead of me on the campaign trail — a search for candidates who may lift the gloom and restore some faith in the principled politics so lacking in Washington these days.

President Barack Obama, who seemed to embody those hopes two years ago — as did the man we knew historically as John McCain — recently crystallized the disillusionment in back-to-back performances.

Addressing a Muslim gathering in the White House, Obama was the eloquent espouser of high moral principle, arguing for the unquestionable right of a Muslim charity to build a community center and mosque in the neighborhood of the World Trade Center, site of the 9/11 massacre.

The next day, panicked by evidence of public disagreement with his stand, he backtracked more than half way to assert he was not recommending any such project.

What a stand-up guy. And what a stand-up party, whose Senate majority leader, Harry Reid, capsulized the same equivocation in a single formal statement, coming out simultaneously for and against the mosque.

Here is the question they are evading: If ground zero is “sacred ground,” as some argue, because of the nearly 3,000 lives that were lost there to savagery, then, should it not be shared with any religious building? Would a church or a synagogue be equally objectionable as a mosque? If not, then the implicit message is to blame one religion — Muslims — for the actions of al-Qaeda, a leap into stereotyping that is almost racist. Obama had it right the first time, but he couldn’t bring himself to stick to his guns, and Reid treated the issue as he does most things, as less important than his own survival.

So you turn to the Republicans and find — what? A party that claims to deserve political rewards for almost unbroken and increasingly debilitating across-the-board opposition to common-sense measures in the national interest.

You can go back to the fiscal rescue effort in the winter of 2009, when the national economy teetered on the brink of collapse, and only three of more than 200 Republicans in the House and Senate voted for legislation to apply a tourniquet to the bleeding. What irresponsibility.

Look at health care. After many months of foot-dragging and near unanimous voting to preserve a ruinous status quo, Republican leaders now are targeting for retroactive extinction the one feature for the new law that would empower outside experts to do what Congress will not — control costs in Medicare. What hypocrisy.

I could cite more examples, such as when energy and climate change legislation came up for votes, or financial regulation. But let me focus on a report in the Washington Post that the delay in Senate consideration of the new strategic arms treaty with Russia means, as the story said, that “for the first time in 15 years, U.S. officials have lost their ability to inspect Russian long-range nuclear bases.”

The inspections were guaranteed by the old START agreement, which expired last December. The successor treaty was negotiated in April, but the Senate has not taken it up, because several Republican senators have raised questions about its possible effect on plans to modernize the U.S. nuclear fleet.

Republican Richard Lugar, probably the Senate’s leading authority on nuclear disarmament, told reporter Mary Beth Sheridan that the delay “is very serious and impacts our national security.”

But Sen. Jon Kyl of Arizona, the deputy Republican leader and one of the main voices challenging the urgency of action, told Sheridan he had assumed the inspections were continuing. What a price to pay for ignorance.

And what a choice the voters face.

DAVID BRODER’s column is distributed by The Washington Post Writers Group, 1150 15th St., NW, Washington, D.C., 20071. E-mail: davidbroder@washpost.com