In the 11 months since the National Voter Registration Act -- popularly known as the "Motor Voter Law" -- went into effect, more than a million Americans a month have been signing up at driving permit bureaus and other government service offices, better than twice the usual rate.
But will people who register while routinely getting a driving permit or visiting a welfare office turn out on Election Day?
Will they be as motivated to vote as people who make the traditional trip to a registrar's office?
Preliminary results are not very encouraging for proponents of the Motor Voter measure, especially designed to reach the young and poor.
In Kentucky's gubernatorial primaries last spring, fewer than 7 percent of the people who registered between January and May while getting a driving permit turned out to vote.
And of those who registered in that period at social services offices while getting food stamps, Medicaid or some other government assistance, fewer than 5 percent voted.
By contrast, the turnout rate was about 25 percent for Kentuckians who registered between January and May through the traditional manner of going to a registrar's office, the so-called "motivated walk-ins."
"Motor Voter is a howling success as a registration tool, but turnout is still a dog," said Bob Babbage, Kentucky's secretary of state and its chief elections officer.
"Even granting that Kentucky has never been a great state for turnout and that primaries hardly ever draw like main elections, it's clear from these new figures that this country's next great political challenge is to find a way to boost turnout."
Mr. Babbage said the turnout percentages for Kentucky's fall election, potentially a bigger and better measure of voting trends, will not be fully compiled for several more months.
Meanwhile, the few other states that have held statewide elections thus far this year, an "off year" nationally for political contests, have not yet broken down their results.
Voter registration and voter turnout have been a nagging political problem in the United States for many years, increasingly so as voters have become more dissatisfied with the country's institutions and political direction.
Only about two of every three Americans of voting age are registered, with notable absences among the young and the poor -- the main targets of the Motor Voter Law.
As for turnout, in recent decades it has reached a high of about 55 percent of the voting-age population during presidential election years, then typically has fallen off to about 35 percent during years in which interim congressional elections are held.
According to Curtis B. Gans, director of the Washington-based Committee for the Study of the American Electorate, there was never any great expectation that the Motor Voter Law would greatly increase voter turnout.
"The motivation factor was always one of the big ifs," he said. "But first you have to get people on the rolls. Then you can work on getting them to the polls.
"Still, I would have thought the Kentucky percentages would have been somewhat better, even considering that they come from a primary."
