One of the bits of conventional wisdom from Election 2004 is that President Bush benefited in many states from conservative ballot initiatives -- especially those opposing gay marriage -- which whipped up passion and turnout among the conservative base.

But how much did these initiatives really contribute to Bush's victory? Paul Taylor the Pew Center recently surveyed the 11 states that voted on gay marriage, and whether this "wedge issue" helps explain Bush's victory. His findings:

Yes, it's true that Bush carried nine of the 11 states where the gay marriage bans were on the ballot in 2004. But it's also true that, unaided by gay marriage ban initiatives, Bush won those same nine states in 2000.

Yes, it's true that, in the aggregate, Bush increased his percentage of the vote in those 11 states by two percentage points between 2000 and 2004. But across all 50 states, he upped his percentage of the vote by three percentage points.

And yes, it's true that turnout spiked in those 11 states by 18.4% between 2000 and 2004. But nationwide, turnout was up by nearly as much -- 16%. And in Red America (the 31 states that Bush carried in 2004), turnout was up a bit more -- 18.9%.

In short, toting up all these numbers, it seems safe to say that the 11 gay marriage initiatives had no across-the-board impact on the 2004 presidential race.

But he does leave open one possible exception -- and it was a critical one:

Despite the voting patterns described above, the gay marriage issue might -- might -- have contributed to Bush's victory in Ohio, which turned out to be the pivotal state of the 2004 election.

[O]ne set of Ohio findings from the VNS exit poll is especially intriguing. Even though Bush improved his overall share of the vote in Ohio by just one percentage point from 2000 (50%) to 2004 (51%), he registered much bigger gains among three groups that strongly oppose gay marriage -- blacks (Bush got 16% of the black vote in Ohio in 2004, up from 9% in 2000); those who attend church more than once a week (Bush got 69% of those votes in 2004, up from 52% in 2000) and voters ages 65 and older (58% in 2004, up from 46% in 2000).

Of course, Taylor is only looking at the impact of one initiative on one presidential race. The impact in other situations, and on down-ballot races may be different.

It's also true that ballot initiatives may have a more long-term impact on the political debate -- forcing certain issues to the top of the agenda, framing the discussion, developing a public consensus around conservative or progressive positions.

As the state policy group Progressive States argues in a recent newsletter,

There are few more potent tools for impacting the outcomes of elections than changing what appears on the ballot. And there are no more direct paths from public outcry to passed legislation than through ballot issues. For years, the rightwing has been advancing policy goals, shaping message, and marshalling voters through ballot issues (we've already highlighted many of their current-year endeavors in this very newsletter). Progressives increasingly are fighting back using ballot issues -- which shouldn't be surprising, since initiatives and referedenda were originally a progressive reform.

In addition to minimum wage initiatives, pioneered by Florida in the 2004 elections, Progressive States points to three other areas where progressives are taking their issues to the ballot: stem cell research, clean energy, and pro-democracy reforms aimed at campaign contributions, lobbying and ethics.

For more information, visit the Ballot Initiatives Strategy Center, which Progressive States rightly calls "the go-to source of information for progressives" on these issues.