(CNN) - A new poll indicates that a split on the right could allow Democrats to take over a congressional district they haven't won in generations.
According to a Siena College survey released Thursday, 33 percent of likely voters in New York's 23rd congressional district support Democrat Bill Owens, with 29 percent backing Republican Dierdre Scozzafava and 23 percent supporting Conservative Party candidate Doug Hoffman.
Scozzafava's dropped 6 points over the past two weeks, with Owens now up 5 points and Hoffman jumping 7 points. The Democrat's 4-point lead over the Republican is within the poll's sampling error.
The election in the three-way race to fill a vacant congressional seat is 19 days away. The office opened up after nine-term Republican Rep. John McHugh stepped down after being confirmed as Secretary of the Army. The largely rural district spans 11 counties in northern New York.
Republicans have represented this area of the state since 1872. McHugh never won less than 60 percent of the vote in his nine election victories, but Barack Obama did edge out John McCain in the district in last year's presidential election.
Scozzafava won the nomination in a vote taken by the 11 GOP county chairman in the district, rather than through a traditional primary election. The local Republican leaders picked the state assemblywoman, who is also backed by the National Republican Congressional Committee, because they felt her moderate views would appeal to centrist Republicans, independents, and even some Democrats.
The move sparked a revolt among many conservatives, who are angry with what they call her liberal views on same-sex marriage and abortion. They are backing Hoffman, an accountant, who is running on the Conservative Party line.
The poll indicates that Scozzafava is edging out Hoffman 40 percent to 27 percent among Republicans - but that 13 point lead is down from a 25 percent margin two weeks ago. According to the poll, 31 percent of independent voters back Hoffman, with 28 percent supporting Owens, a lawyer, and 24 percent backing Scozzafava. The survey suggests that Hoffman's gained 11 points among independents over the past two weeks.
Over that time period, the fiscally conservative Club for Growth and the Hoffman campaign have both hit the air with spots that paint the third-party candidate as the race's true conservative candidate.
"Scozzafava's seven-point lead has evaporated over the last two weeks, as voters have gotten to know all the candidates better," says Siena pollster Steven Greenberg. "Hoffman remains the least known candidate. Nearly half of those who say they are voting for Hoffman don't know enough about him to have a favorable or unfavorable opinion of him."
"There is a big geographic split in the district, which stretches across more than 200 miles and parts of 11 counties," says CNN Polling Director Keating Holland.
"According to the Siena poll, the Republican is ahead in the Watertown media market along the St. Lawrence river and the upper reaches of Lake Ontario. The Democrat has an advantage near the Vermont border and into the Albany media market. And the poll indicates that the third-party candidate may have the edge in the Syracuse media market at the western edge of the district."
The Siena College poll was conducted Sunday through Tuesday, with 617 likely voters in New York's 23rd congressional district questioned by telephone. The survey's sampling error is plus or minus 3.9 percentage points.