A party spokesman blames the fight over illegal immigration.
Whatever the reason, only a few Arizonans appear to be interested in registering as Democrats.
New figures Thursday from the Secretary of State's Office show the party has picked up fewer than 1,700 new adherents since the August primary. By contrast, Republican Party registration is up by more than 12,000.
But the bulk of those who have signed up to vote in next week's general election are not interested in either party: Total registration of independents is up almost 29,000.
The new numbers put the Democratic party, which has been losing strength relative to Republicans for years, perilously close to running third, behind the independents. In fact, just 20,460 voters separate Democratic registration from independents.
Potentially more telling is what has happened since the 2008 election.
Democratic Party spokeswoman Jennifer Johnson said it's not unusual for voter registration to drop off after a presidential election year. And that is true this time -- at least for the Democrats who shed close to 20,000 registrants.
But the Republican Party managed to buck that trend in Arizona, increasing its strength between the 2008 general election and now by more than 13,000.
Johnson says the GOP is taking advantage of the high-profile fights between Arizona and the federal government.
"What makes a difference is what happened this summer,'' she said. Johnson said that includes the lawsuit by the Obama administration to void the state's new immigration law and "all the ongoing battles that have been played out in a very high-profile way by the governor.''
She conceded the popularity of the new law, saying that SB 1070 "has been co-opted by everybody all the way down on the ballot.''
In fact, it has forced many Democratic candidates who have expressed concerns about the bill to find ways to explain that.
For example, gubernatorial hopeful Terry Goddard said he believed the original version signed by Gov. Jan Brewer was illegal. Only after changes were made, he said, did he consider the measure legally defensible.
And Felecia Rotellini, running for attorney general, said she opposed SB 1070 saying it doesn't go far enough.
Johnson said that the anemic change in Democratic registration doesn't mean that people are not signing up with the party. She said it's possible that the net figure of 1,681 reflects that some people who had previously been registered as Democrats were becoming independents.
She said party figures show about 13,500 people became newly registered Democrats in the last three months.
"You have a frustrated electorate that in many cases is very angry,'' Johnson said. "And they're angry about things that are not being done quickly enough or the federal government not doing its job in a way the electorate is happy with.''
She said that frustration is being vented against the Democrats as the party in power, at least in Washington.