BELLEVILLE — Adjutant General William Enyart, who who has headed the Illinois National Guard for the past five years, stepped down from that post Thursday saying he would have to do that to run for an open congressional seat.

But Enyart refused to reveal if he will run for the vacant 12th Congressional District seat that U.S. Rep. Jerry Costello, D-Belleville, will vacate after this term.

Enyart submitted his resignation and then talked to a crowd of supporters Thursday afternoon at Belleville's Public Square.

The Belleville attorney said that he was amazed at all the encouragement he has received asking him to run.

"Since my name has surfaced as a possible candidate to be the Democratic nominee for the 12th Congressional District, I have been overwhelmed by encouraging calls and emails from folks across Southern Illinois," he said. "I'm honored and humbled by this outpouring of support so it's time for my family and me to take some time together to weigh the question of how to best serve the citizens of this great state."

Enyart, 62, said he would take a few days to think about whether to run and consult with his family.

"I'll probably be making a decision next week," he said. "In this age, no matter who runs, there will be attack ads and before my family has to face this sort of prospect we need time to think about it."

Enyart said last week that Democrats in the 12th District approached him about replacing Brad Harriman. Harriman dropped out of the race as the Democratic nominee, citing a worsening but not life-threatening neurological condition.

Enyart hasn't held an elected public office before.

A major general, Enyart served as chief of the Illinois National Guard for five years.

In September, Enyart received the Polish Army Medal Gold and last month got the Commanders Cross of the Order of Merit of the Republic of Poland for international cooperation.

Enyart said he was required to give up his National Guard job if he wanted to run for Congress.

Enyart confirmed last week that Democrats approached him about entering the race.

Democrats in the 12-county 12th U.S. House District -- which stretches from Alton in the north to Cairo in the southern tip of the state -- are seeking a candidate to replace Harriman, the winner of the March 20 primary.

Any Democrat interested in the position can request an application by emailing 12thcd@gmail.com. The deadline is 5 p.m., June 15.

Barb Brown, co-chair of the selection committee, said she will send back an application and other information to those who email. She said they received 10 requests in the first 24 hours after publicizing the information over the weekend. But no one has returned an application yet.

While each Democratic leader in the 12th District's 12 counties will have input on the naming of Harriman's replacement, the greatest weight will be given to the Democrats in St. Clair County, which has the district's highest population and had the most Democratic voters in the primary.

Jason Plummer, the Republican nominee for the 12th Congressional District seat, released a statement after Enyart's announcement:

"With reportedly more than a dozen individuals expressing their interest in the position, I anticipate the Democrats having an open and transparent procedure to select their nominee," Plummer said.

"Once a nominee is chosen, I look forward to having serious, civil discussions with the candidate on the issues that impact the residents of the 12th District," Plummer said.

Contact reporter Wally Spiers at wspiers@bnd.com or 239-2506.