Almost 70,000 mail-in ballots have been received by the Lake County Clerk's Office, but they have not yet been counted, according to a report by the Illinois State Board of Elections.
The number of uncounted ballots is enough to swing several races, including some that affect neighboring McHenry County.
One of the closest races on the list is the contest for Illinois' 14th Congressional District, in which incumbent Democrat Lauren Underwood remains 895 votes behind Republican state Sen. Jim Oberweis.
Mail-in ballots in that race have favored Underwood.
In Lake County, Oberweis received 65% of the votes cast on Election Day, 56% of the votes cast during early voting and, so far, 29% of the votes cast via mail-in ballot. Underwood, on the flip side, received 35% of the votes cast on Election Day, 44% of the votes cast during early voting and, so far, 71% of the votes cast via mail-in ballot.
Two of the five Illinois House districts that include parts of McHenry County also fall into Lake County.
They are District 64, currently represented by Republican Tom Weber, who was leading in his reelection bid over Democrat Leslie Armstrong-McLeod, and District 52, currently represented by David McSweeney, who decided against running for another term.
Barrington Hills Village President Martin McLaughlin, a Republican, was leading over Marci Suelzer, D-Island Lake.
An additional 40,641 mail-in ballots also had been requested by voters but have not been returned, as well as 1,815 provisional ballots that were cast in person that have not yet been counted, according to the ISBE.
As long as mail-in ballots are postmarked by Election Day and received by Nov. 17, they are to be counted. Voters who cast provisional ballots have until Nov. 10 to resolve the issue that led to their votes being cast provisionally.
The Lake County Clerk’s Office has said on its results page that it plans to update its vote-by-mail totals after 5 p.m. Nov. 10 and would finalize the results with the remaining vote-by-mail and provisional ballots after 5 p.m. Nov. 17.
McHenry County had received 1,114 mail-in ballots that have not yet been counted as of Thursday, according to the state report. An additional 1,207 voters cast provisional ballots that have not yet been rectified, and 16,160 mail-in ballots had been requested but not returned.
McHenry County Clerk Joseph Tirio has said he would be updating the county’s results page Nov. 18 after the two-week canvassing period ends.
The other counties neighboring McHenry County also have far fewer uncounted ballots than Lake, although Cook County has not yet reported its figures to the ISBE, the report shows.
Kane County had 1,505 ballots received but not counted as of Thursday, all of which were mail-in ballots, according to the report. An additional 7,939 mail-in ballots had been requested but not yet returned.
DeKalb County had 216 ballots received but not counted as of Thursday, according to the report. All but two of those were mail-in ballots. An additional 1,262 mail-in ballots had been requested but not yet returned.
Boone County to the west had 125 mail-in ballots received but not counted, as well as an additional 44 provisional ballots pending as of Thursday, according to the report. An additional 672 mail-in ballots had been requested but not yet received.