U.S. Rep. Jesse Jackson Jr. is the favorite among possible replacements to fill the U.S. Senate seat to be vacated by President-elect Barack Obama, a new Zogby telephone poll shows.

The survey, conducted Wednesday to Thursday, shows that, given a choice of 10 possible candidates, 21 percent think Gov. Rod Blagojevich should appoint Jackson to the seat when Obama leaves it vacant to ascend to the presidency. Tammy Duckworth, a former Democratic congresswoman candidate from a suburban Chicago district, is the only other potential candidate to win double-digit support - 14 percent.

The telephone survey was commissioned by the Jackson campaign and was conducted using live interviewers calling from Zogby's in-house call center in Upstate New York. It included 802 likely voters statewide in Illinois from across the political spectrum. The poll carries a margin of error of plus or minus 3.5 percentage points.

Support levels for other candidates are 6 percent for Rep. Jan Schakowsky, 4 percent for Rep. Danny Davis and 4 percent for state Sen. James Meeks. Several other candidates received less than 1 percent.

The poll also indicates Jackson would fare well in two prospective Senate races. Jackson would defeat Republican Rep. Ray LaHood by a 50 percent to 31 percent margin, the survey shows.

In a prospective match-up against Republican Rep. Mark Kirk, Jackson would win 48 percent support, compared to 32 percent for Kirk, according to the poll.