Conservative state senator Chris Lauzen and Oberweis have been in a fierce battle to win the support of Republican voters for the February 5 primary. Two internal polls within the last month from both leading campaigns show both candidates neck-and-neck for the lead.
A third candidate with a more moderate profile, Geneva mayor Kevin Burns, lagged well behind in both polls.
One Illinois-based GOP operative said Hastert’s decision has the potential to give Oberweis a significant boost.
“His endorsement carries a lot of weight with folks out there,” the operative said. “They’re on a first-name basis with him.”
Just several days ago, Lauzen wrote a sharply-worded letter to Hastert, urging him not to take sides in the primary.
"Now that you are stepping away from your official duties," Lauzen wrote. "I believe that citizens and voters would be distressed if you reassert yourself and use your considerable clout to influence the outcome of an impending primary."