WASHINGTON – Politicians under stress tend to confirm, not refute, the criticisms that got them into trouble in the first place. Vacillating politicians vacillate. Thin-skinned politicians explode.

Democrats are now feeling enormous political stress. Independents have fled the Obama coalition, largely out of concern about debt, deficits and spending. Intensity is all on the Republican and conservative side. A recent Gallup poll found that the percentage of Republican voters who say they are “very enthusiastic” to vote in 2010 is twice the percentage of Democrats who say the same (44 percent to 22 percent). President Obama’s job approval now flirts with 40 percent, with solid majorities disapproving his handing of the economy, deficits and health care.

On this trajectory, Democrats see the House slipping away, their Senate majority threatened, and a president now too divisive to profitably appear in many districts.

So how have national Democrats decided to respond? With a series of tactics that make their worst problems worse.

First is the depiction of Republicans as the “party of no,” populated by obstructionists blocking needed measures to create jobs and improve the economy. Vice President Joe Biden recently applied this critique to the stimulus package. “There’s a lot of people at the time argued it was too small,” he said. If it had not been for Republican opposition, “I think it would have been bigger.” No doubt it would have been.

This is Biden’s response to American economic anxiety: If Democrats had even greater control in Washington – even larger influence than holding the presidency and both houses of Congress – they would have spent more than $862 billion on the stimulus. Rather than allying the fiscal concerns of independents, Biden is actively feeding these fears – thereby making the case for the moderating effects of divided government.

With health reform and massive spending, Democrats have picked a fight on the size and role of government. The Republican response, at this point, consists mainly of yelling “Stop!” In a presidential race – which demands a positive domestic agenda – this would not be sufficient. In a midterm referendum on the performance of the president and Congress, it seems like more than enough.

A second tactic has been to identify Republicans with tea party extremism, the way Democrats once tried to identify Republicans with the religious right. As in that earlier case, there are extremes that deserve criticism. But about a quarter to a third of Americans identify in one way or another with the tea party movement. As William Galston of The Brookings Institution points out, Americans currently place themselves on the ideological spectrum closer to the tea party movement than they do to the Democratic Party, which they view as increasingly liberal.

Crude Democratic attacks on the tea party offend a broad group of voters. And the political intensity of conservative populists is only increased by elite disdain.

The third response to declining Democratic fortunes is to blame George W. Bush – Obama’s currently favored tactic. This week, Obama both ripped Bush for the economic problems of the country and tried to swipe credit for the successes of Bush’s Iraq strategy (a strategy that Obama vigorously opposed).

The problem for Democrats is the contrast. Most would concede that former President Bush has been tremendously classy since leaving office, not only refusing to take the bait of criticism but agreeing to help with the American effort in Haiti when Obama asked. Of Obama’s behavior, “classy” is not the adjective that comes to mind. Instead, Obama’s self-serving criticism seems small, petty and shirking. In a nation increasingly skeptical of the president’s leadership style, Obama is adding to those concerns.

Blaming Bush becomes less credible over time. After 18 months dominating every elected branch of government and fulfilling many of their legislative wishes, Democrats seemed surprised by the arrival of accountability. On the economy in particular, investors and job creators don’t make decisions based on blame; they make decisions based on confidence in current policies. Right now, they see endless deficits and likely tax increases. And they have little reason for confidence.

It seldom works in politics to respond to a coming political wave with marginal changes in political tactics. Parties generally don’t shift their policies or moderate their ideology until after they are well and truly walloped by voters. But Democrats under stress are actually complicating their own task – further alienating independents, provoking conservative intensity, practicing an unattractive pettiness, and making a walloping in November more likely.

© 2010, Washington Post Writers Group