Republican Bob Turner holds a commanding lead of six points in the latest poll in the special election to fill Anthony Weiner’s seat, conducted independently by Siena College. Crucially, he also now has 50 percent of the electorate, leading Democrat David Weprin 50-44.

Previous polls had shown him in the lead, but were potentially biased by GOP ties. This is a remarkable reversal; the last Siena poll, from August 15, placed Weprin six points ahead (though even this was considered a strong Republican showing in such a blue district).

This news comes after Democratic PACs and other committees significantly increased involvement in the race yesterday, only to see their half-million-dollar TV buy backfire — Weprin’s latest ad showed a jet emblazoned with Turner’s name flying through the New York skyline, causing many to note an eerie connection to 9/11.

I noted earlier this week the similarities and differences between this campaign and Scott Brown’s upset in Massachusetts last year. One other emerging difference may be that, in contrast to Scott Brown’s successful Tea Party fundraising, Turner’s campaign is still at a huge funding disadvantage and may succeed on political savvy and negative sentiment alone — though one can hardly put a price on an endorsement by Donald Trump, who was featured in robocalls for Turner yesterday.

A Republican victory in a district which has elected Democrats since 1923 would represent a priceless repudiation of Obama’s policies on debt and Israel. The special election is on Tuesday.