WASHINGTON — On a drive to turn the Senate Democratic, Vice President Joe Biden hits Chicago on Sept. 28 to headline a fundraiser with Sen. Dick Durbin to help Rep. Tammy Duckworth defeat Republican Sen. Mark Kirk.

This funder will be at the North Side home of Fred Eychaner, the Chicago business executive who is one of the nation’s biggest donors to Democratic candidates and causes. Durbin, the senior senator from Illinois, is the No. 2 Democrat in the Senate.

The contribution level, according to the invitation, runs from $12,500, which includes a photo reception and a dinner, to $36,100, which also gets the contributor a VIP reception.

The money will go to the Illinois Victory 2016 fund, a joint fundraising committee to benefit the Tammy for Illinois committee, Duckworth’s main campaign war chest and the Democratic Senatorial Campaign Committee, the Democratic Senate political operation.

Biden has headlined fundraisers for a string of Democratic Senate hopefuls, including an event for former Sen. Russ Feingold, who’s in a Wisconsin rematch against Sen. Ron Johnson.

The Illinois and Wisconsin Senate contests are among the best Democratic bets for pick-ups.

At present, Republicans have 54 Senate seats. The Democrats’ hold 46, including the independents who caucus with the Democrats. There are 34 seats in play in November; 24 of them are held by GOP senators. To win control of the Senate, Democrats need four more seats if Hillary Clinton wins — because her vice president can cast a vote to break a tie — and five more seats if Donald Trump wins.