Montana Republicans appear to be pulling one of the oldest tricks in the book to keep Democrats away from the polls this November.

The state party is challenging the eligibility of 6000 registered voters -- or almost one percent of registered voters in the state -- claiming that these voters are registered under incorrect addresses, reports the Missoulian. And many of the counties in which the challenges are occurring represent pockets of Democratic strength in the largely red state.

The state GOP appears to have gone to some lengths to actively identify these voters. It obtained a commercial software system used by direct marketers that contains a nationwide list of people who have changed their addresses. Then it compared that list to a new statewide voter database, in order to find people who are living somewhere other than where they're registered to vote. It says it then issued challenges with election officials against these people.

But the challenges were made in only seven counties, most of which turned out to be Democratic-leaning. In 2004, only six of Montana's 56 counties voted for John Kerry over George Bush. Four of those counties are among the seven in which the GOP is challenging voters.

As a pretext for the move, Jacob Eaton, the state party's executive director, cited recent comments by Democratic governor Brian Schweitzer. In July, Schweitzer told a meeting of trial lawyers that he helped "turn some dials" to get fellow Democrat Jon Tester elected to the Senate in 2006, saying that he helped remove GOP poll-watchers from Indian reservations, and pressed the Associated Press to call the race for Tester. Schweitzer has since said his comments were intended to be humorous. But Eaton told the Missoulian that the remarks "brought everyone in the state to a new level of suspicion and awareness of the integrity of our elections."

The stakes could be high. Polls over the summer showed Barack Obama running close with John McCain in the presidential race -- though recently McCain appears to have widened his lead.