It’s a time of trial for the Democratic Party. The labor movement is split. Left-center squabbling has surfaced anew. The party still has no positive agenda. And the Supreme Court is heading further to the right.

Moreover, President Bush’s approval ratings are edging back up — to 49 percent in the latest Gallup poll. The economy is strong and the deficit is falling, even if only temporarily. And the country’s first impression of Bush’s Supreme Court nominee, John Roberts, is positive. [IMGCAP(1)]

Roberts presents Senate Democrats, including four of the party’s 2008 presidential candidates, with a special dilemma: Do they signal to the country that they are looking for reasons to oppose him, or are they bent on fair inquiry into his fitness for the high court?

Another way of expressing the question is: will they come off as dependable tools for the liberal interest groups who’ll demand opposition to any conservative, or can they execute a “Sister Souljah” maneuver akin to what then-candidate Bill Clinton did to distance himself in 1992 from a controversial rapper?

The evidence is not good on one score: Overwhelmingly, House Democrats — even the moderate “New Democrats” — are expected to oppose the Central America Free Trade Agreement, caving in to naked threats from the labor movement.

Even as labor was plunging into civil war in Chicago, 20 of its chieftains issued a ukase to the Democratic party: “Our work to help elect at-risk members … will not extend to those who vote against us on this issue. … We cannot and we will not give any Democrat a pass on CAFTA.”

In 1993, by contrast, similar threats came from labor, but 102 House Democrats voted for the North American Free Trade Agreement anyway, backing Clinton, who said the fundamental issue was “whether we will embrace change and create the jobs of tomorrow, or try to resist those changes, hoping we can preserve the economic structure of yesterday.”

Trade between the United States, Canada and Mexico has practically tripled since NAFTA’s enactment, and the U.S. unemployment rate has fallen, not increased. Yet labor — and, increasingly, Democratic politicians — oppose free trade.

Significantly, the Democrats’ 2008 front-runner, Sen. Hillary Rodham Clinton (N.Y.), is also against CAFTA, even though she’s aligned herself with her husband’s old group, the centrist Democratic Leadership Council, and has volunteered to develop new ideas for the party.

When CAFTA came up for a vote in the Senate on June 30, she was joined in voting “no” by all three other prospective Democratic contenders, Sens. Evan Bayh (Ind.), Joseph Biden (Del.) and John Kerry (Mass.) — Bayh is the outgoing chairman of the DLC.

Still, Clinton’s speech to the DLC in Columbus, Ohio, sent positive signals to the country about the Democratic party: The front-runner is working on a positive agenda, not just confining herself to anti-Republican name-calling, the stock in trade of the MoveOn.org-Michael Moore-Howard Dean wing of the party.

Taking over as head of the DLC’s “American Dream Initiative,” Clinton delivered a kind of “I have a dream” speech about the world as it could be in 2020 if correct policies were followed.

She led off by addressing the Democrats’ chronic weakness — lack of the public’s trust on national security — and made it clear that she intends to find space to Republicans’ right on the issue of keeping the country safe.

She envisioned “a coherent strategy focused on eliminating terrorists wherever we find them,” “protecting our borders,” “hardening nuclear, chemical and other sensitive sites,” “securing mass transit” and giving local police better equipment and training.

She advocated increasing the size of the armed forces, providing them with better equipment and upgrading U.S. intelligence. She also bowed in the direction of Kerry’s 2004 campaign, promising to “re-engage with the world on a range of global challenges that can only be solved with global coalitions.”

She also, in effect, promised to develop a positive domestic agenda involving “patient-centered health care,” giving all children “more choices about what public school to attend” and tax reform that will “favor work over privilege, productive investment over non-productive ones.”

Even though Clinton indulged in her share of Bush-bashing and called for unity in the Democratic party — even chiding the DLC for sowing discord in the past — she immediately got socked by various left-wingers for aligning with centrists.

As one former party official observed to me, even with the full assistance of labor and an energized left that turned out a near-maximum Democratic vote, Kerry fell short in 2004 because he lacked a message that appealed to growing areas of the country, especially exurbs.

Democrats significantly increased their turnout in cities such as Cleveland and Philadelphia from 2000 to 2004, yet they lost ground statewide because the GOP increased its turnout in nonurban areas even more.

The DLC’s idea is to expand the party’s appeal in America’s “heartland,” and it has attracted, beyond Clinton, such 2008 candidates as Iowa Gov. Tom Vilsack and Virginia Gov. Mark Warner. But the effort got attacked by the left.

In the meantime, labor has fractured over — among other things — the issue of how much union resources should be devoted to politics versus basic organizing.

Some optimists hope that competition between the John Sweeney-led AFL-CIO, which favors politics, and the Andrew Stern-led rebel unions, which favor organizing, could lead to a net increase in election-year activity on behalf of Democrats.

But most party analysts expect that there will be less manpower and money available for political work and issue ads.

On top of all this, there’s also the challenge of the Roberts nomination. So far, Senate Democrats have handled the challenge of the attractive, but ideologically elusive, nominee with aplomb, appearing to look for data rather than appearing obstructionist.

Sen. Charles Schumer (D-N.Y.) presented Roberts with what amounts to an 11-page take-home exam that should set up fascinating confirmation hearings in which Democrats try to tease out information on Roberts’ attitudes on legal and social issues and he tries to sidestep commitment on cases that might come before the court.

But if Roberts comes off as a solid conservative, not an extremist or ideologue, what do Democrats do? The evidence of CAFTA suggests that they aren’t capable of Sister Souljah moments.