Indiana’s four candidates for secretary of state will meet Wednesday night for their second debate as a closely watched race enters its final weeks and campaign spending intensifies.

Republican Max Engling, Democrat Beau Bayh, Lincoln Party candidate Greg Ballard and Libertarian Lauri Shillings are scheduled to participate in the hour-long Indiana Debate Commission event beginning at 7 p.m. Eastern at WFYI studios in Indianapolis. University of Indianapolis political science professor Laura Merrifield Wilson will moderate.

The debate comes less than four weeks before the Nov. 3 general election and as recent polling suggests Engling and Bayh are separated by only a few percentage points. Ballard and Shillings have registered in the single digits in some polling, although Ballard’s campaign has questioned whether the surveys accurately measure his support.

The race guarantees Indiana will have a new secretary of state. Incumbent Republican Diego Morales lost his party’s nomination to Engling at the state convention in June.

Campaign money has emerged as one of the latest flashpoints.

Bayh has received more than $1 million from donors outside Indiana, including contributors with connections to his father, former U.S. Sen. Evan Bayh. His overall fundraising is expected to exceed $4 million when the next campaign finance reports are filed Oct. 16, including $1 million recently contributed by the Indiana Democratic Party.

Engling’s campaign says it has raised more than $2 million since he entered the race in May. That includes $1 million in support from the Indiana Republican Party and Gov. Mike Braun’s campaign fund. Former U.S. House Speaker Kevin McCarthy, for whom Engling previously worked, also contributed $50,000 through his campaign fund.

Both major-party candidates have faced criticism over individual donors.

Democrats have criticized Engling for accepting $50,000 from Noblesville businessman Michael Sherfick, who pleaded guilty to federal bribery charges in 2010 and later served a prison sentence. Engling has defended accepting the contribution, noting Sherfick completed his sentence years ago and is legally permitted to make campaign donations.

Engling, meanwhile, has criticized Bayh for accepting $25,000 from Apollo Global Management CEO Marc Rowan, whose past communications with convicted sex offender Jeffrey Epstein appeared in Justice Department documents. Rowan has not been accused of wrongdoing involving Epstein, and Apollo has said Rowan did not have a business or personal relationship with him.

The candidates have also traded attacks over their ties to Indiana. Republican advertising has questioned Bayh’s Indiana voting history during years he lived outside the state for school and military service, while Engling has faced criticism over the roughly 12 years he spent working in Washington. Ballard, a former Republican mayor of Indianapolis, has also faced criticism over time he spent living in South Carolina after leaving office.

Wednesday’s debate could also revisit disagreements that surfaced when the candidates met in August.

Bayh, Ballard and Shillings said during that debate they would support an audit of the secretary of state’s office following controversies surrounding Morales’ tenure. Engling did not make the same pledge, saying his successful challenge to Morales for the Republican nomination was part of an effort to restore confidence in the office.

The candidates have also differed over voting rules and proposals aimed at increasing voter participation. Ballard has proposed sending a voter guide to every registered voter, while Engling and Bayh have questioned the estimated $2.5 million cost.

More recently, Ballard called for state lawmakers to prohibit future secretaries of state from endorsing, fundraising for or donating to political candidates. Ballard argues the state’s chief election officer should avoid partisan political activity. Engling’s campaign responded that he has already pledged not to use the secretary of state’s office for campaign activities.

The secretary of state serves as Indiana’s chief election officer and also oversees business services, securities regulation and other functions.