WASHINGTON — Sen. Mark Kirk, R-Ill., and his rival Rep. Tammy Duckworth, D-Ill., are in a statistical tie, according to a new Kirk poll, with Duckworth slightly ahead and Kirk’s role in the Merrick Garland Supreme Court fight burnishing an independent image.

The Kirk campaign shared some of the poll findings with the Chicago Sun-Times, but not the entire survey. Kirk is considered one of the most at-risk Senate Republicans up this cycle, running in a state expected to produce a heavy Democratic presidential vote in November, no matter who the nominees are.

It’s unusual for any findings of a poll to be released showing an incumbent behind. But the Kirk campaign, in a difficult political climate in Illinois, wants to send the message that the Senate race is in play.

Indeed, hours after I broke a story about the poll on Tuesday morning, both Kirk and Duckworth sent out email fundraising appeals pegged to the survey. Duckworth’s pitch: She needs money to keep her lead. Kirk’s request for contributions in his email said though “locked in a statistical tie,” “Mark has all the momentum.”

The Senate survey, by Kirk’s pollsters, the GS Strategy Group, was of 600 likely general election voters and taken March 30-31, after Kirk and Duckworth won their party nominations in the March 15 primary.

In the direct matchup, Duckworth led 42.7 percent to 39.6 percent for Kirk, with about 18 percent undecided.

The survey’s margin of error is plus or minus 4 percentage points. I was given a copy of a GS Strategy Group memo about the Kirk poll and I was provided with some supplemental information.

The Illinois Senate contest “remains incredibly tight,” GS founder Greg Strimple wrote in his memo.

Duckworth pollster Jill Normington, writing a rebuttal memo, concluded that the Kirk poll memo release “is a clear sign that Kirk is in trouble, and that his only hope is to scare voters. His internal numbers show him to be weak.”

To win a second term, Kirk will need an outpouring of independent and crossover Democratic votes.

Kirk, who speaks Spanish, polled better than Duckworth among Hispanic voters — 44 percent to 39 percent — though that lead is within the margin of error. Duckworth has the overwhelming advantage among African-American voters: 70 percent to 12 percent.

The Garland confirmation battle is fertile for Kirk, who was an early supporter of President Barack Obama’s right to tap a replacement for Justice Antonin Scalia, saying so soon after the justice died on Feb. 13.

By 64.3 percent to 31.3 percent, Illinois voters agree that the Senate should hold hearings and vote on Obama’s nominee, according to the poll.

Last week, Kirk became the first Republican senator to meet with Garland, a federal appellate judge. Garland, a Chicago native, was raised in north suburban Lincolnwood and is a graduate of Niles West High School in Skokie. Kirk has been out front in breaking with his Senate leadership, urging an end to the blockade around Garland and calling for a confirmation hearing and an up-or-down Senate vote.

About 41 percent of those polled knew of Kirk’s break; 46.5 percent did not know and 12.7 percent thought it was not true.

A key component of Kirk’s re-election bid is highlighting him as a political independent.

Asked whether Kirk is a “thoughtful, independent leader,” about 45 percent agreed and 22 percent disagreed.

Kirk Polling Memo.04.04

Duckworth Public Polling Memo FINAL