It’s clear that Republican candidates for Congress expect to gain traction from the health care bill that Democrats passed this year, and that most polls show at least a plurality of the country remains opposed to. Although most Democratic candidates are willing to address the health care issue, they are having to do so more carefully.

But rather than being a matter of unique importance, health care is instead one of a patchwork of issues contributing to a tricky political environment for the Democrats, an analysis of campaign Web sites suggests, in which they have few forward-looking messages for voters.

With the help of FiveThirtyEight’s news assistant, Micah Cohen, I studied the campaign Web sites of Republican and Democratic candidates for the House in the 33 Congressional districts currently labeled toss-ups by The New York Times political desk. Although a few candidates did not highlight particular issues on their official Web pages, and a few others remain engaged in primaries where there is no clear favorite, we were able to examine the sites for 29 Republicans and 29 Democrats who are likely to be on the ballot in November. We then examined the subjects these candidates highlighted on the “issues” sections of their sites, dividing them into roughly 30 categories.

Issues Highlighted on Web sites of Democratic and Republican Candidates in 33 Toss-up Districts

Excluding the broad subject of the economy, which we divided into several subcategories like jobs, taxes and deficits, health care was the most frequently mentioned issue. Of the 29 Republicans in these pivotal districts, all but one mentioned it, with many suggesting that the Democrats’ bill should be repealed. But health care was also highlighted by 23 of the 29 Democrats, making it the most cited issue among that party as well.

The Democrats’ message was varied. Some, like Colleen Hanabusa, who is running in Hawaii’s First Congressional District in Honolulu, had clear praise for the Democrats’ health care goals. Others, like Representative Stephanie Herseth Sandlin, a moderate Democrat from South Dakota who voted against the bill, lauded some of the bill’s achievements, while criticizing other provisions and calling for further reform.

Still, most Democrats were willing to engage their constituents on the issue. And beneath the surface, their message was fairly consistent. Most Democrats –- whether they voted for the bill or against it –- suggested that it had been a reasonable start and had worthy goals, but that it required further tinkering.

What was more striking in our examination was a Republican agenda that appeared in sharper relief than the Democratic one, and which was more readily contributing to their messages to voters on the campaign trail.

For some Republican candidates, the agenda may indeed begin with the health care bill, which many are pledging to repeal. But there are also issues like the deficit, which more than four out of five Republicans highlighted on their Web sites in some form. Some 60 percent of Republicans, meanwhile -– including some in states far removed from the Mexican border -– addressed immigration, usually advocating tighter border security.

Democrats, on the other hand, are having trouble articulating a clear set of policy goals. After health care, the issues mentioned most frequently by Democrats were energy, jobs and education – each of which were highlighted by 7 out of 10 Democrats. But these issues do not necessarily lend themselves to a crisp set of policy proposals. The country has been debating various efforts at job creation since the start of President Obama’s term, and usually with little consensus. Although Mr. Obama has advanced an education plan, it has received scant attention in Congress, making it hard for Democrats to draw clear contrasts. On energy, the Democrats do have a clearer policy proposal: their bill to introduce a cap-and-trade system, which passed the House last year but not the Senate. Many of the Democrats, however, spoke about “energy independence” in much vaguer terms (as did many Republicans). And a few – like Mike Oliverio, a conservative Democrat in West Virginia — noted their opposition to the cap-and-trade proposal.

Arguably, the frequent mention of education on the Democrats’ Web sites – as well as another issue, veterans’ affairs – speaks somewhat to the weakness of their political position. Few voters will object to these issues: who wouldn’t want to support our children, or our troops? But without specific policy proposals attached to them (and more specifically, policy proposals that Republicans have raised objections to) it is not clear that they will motivate Democratic and swing voters to go to the polls.

Meanwhile, the Democrats in these swing districts are keeping some issues that have traditionally motivated their party’s base in mothballs. Only 4 of the 29 Democrats, for instance, mentioned their position on abortion, even though most polls show that a plurality of voters still support abortion rights. In contrast, the issue was touched upon by more than half of the Republicans.

While many Democrats mentioned energy independence, only a few were willing to couch the debate in terms of the environment, in spite of the oil spill in the Gulf of Mexico and given that the environment remains one of the few issues on which voters still give Democrats a clear edge.

None of the Democrats, meanwhile, mentioned labor organizing rights (and only one Republican did), even though the Employee Free Choice Act – a bill that would ease union formation – ostensibly remains a part of their agenda.

And both Republicans and Democrats avoided the issue of gay rights, where public opinion is shifting. Even if gay marriage were too controversial to be a part of the Democratic agenda in most swing districts, the Democrats might theoretically gain ground by highlighting their support for allowing gay men and lesbians to serve openly in the military, where large majorities of the public back their position. But perhaps hamstrung by Mr. Obama, who has taken a series of half-steps on the issue, few of these Democrats have chosen to do so.

In other ways, indeed, Democratic candidates are handicapped by an ambiguous set of policy priorities advanced by their leadership. Repealing the Bush tax cuts for high-income earners, a priority of Mr. Obama’s on the campaign trail in 2008, remains at least reasonably popular. But that agenda item has been placed on hold as Democrats debate whether any kind of tax increase would be wise while the economy remains sluggish. Meanwhile, although Democrats were more likely than Republicans to mention the war in Afghanistan, their traditional reservedness about military engagements is flummoxed by Mr. Obama’s having expanded troop commitments there.

On other issues, the Democrats are in some ways victims of their own success. That they passed a health care bill, for example — albeit one that much of the public objects to – strikes from their agenda an item that had been a policy priority of theirs for more than half a century. And with the war in Iraq slowly winding down, Democrats can no longer gain ground by pledging a withdrawal from that country, as Mr. Obama did in 2008.

Finally, a few second-tier issues that would seem to be unambiguously good draws for voters have been all but forgotten by the Democrats. Only about a quarter of the Democrats mentioned financial reform, even though they succeeded in passing a bill that received decent reviews from economists and voters. And only 1 in 10 mentioned campaign finance reform, where they would seem to have the more popular position.

Instead, on many issues like health care, Democrats seem to be hoping that the best offense is a good defense. In some cases – like Social Security and Medicare, which Democrats were more likely to mention than Republicans – they may be making an effort to pre-empt Republican proposals to trim the programs, which may emerge during the budgetary debates of the next several years. But whether these issues have yet ripened for voters is unclear.

Democrats have criticized Republicans for their vague agenda – and certainly the Republicans have not articulated anything as succinct as the Contract With America, which aided their exceptional performance in the midterm elections of 1994. But Republicans do appear to have a message that is at least reasonably clear to voters, and reasonably consistent from one Congressional district to the next: pick us, and we’ll repeal health care, secure the border and reduce the size of government. Democrats, meanwhile, who two years ago seemed to have a glut of agenda items, are now having trouble articulating to their constituents exactly what a Democratic vote would gain them. Perhaps that’s why Democrats are having trouble both with the sizable number of voters who are dissatisfied with both parties and in motivating their base.