It depends on what you mean by uncontested races - do we just count districts with only one candidate, or those with only candidates from one major party? In some states, truly uncontested races don't change the total popular vote, as the sole candidate wins the seat without voters actually casting votes - in these midterm elections the uncontested districts in Florida and Louisiana didn't record any votes for the sole candidate.
In total, sixteen seats were completely uncontested; Arizona's 8th & 9th, Florida's 5th, Illinois' 7th, Louisiana's 4th, Massachusetts' 4th, New York's 13th, Pennsylvania's 13th & 14th, South Carolina's 3rd & 4th, Texas' 6th, 11th, 25th & 31st, and Wisconsin's 6th. The seats in Illinois, Massachusetts and New York were won by Democrats, with the rest being won by Republicans. The Cook Political Report currently puts this at 47,244,474 votes for the Democrats, and 52,268,015 votes for the Republicans, for a two-party percentage of 47.48% vs 52.52%. With the votes cast in these completely uncontested districts removed (2,154,009 for Republicans, and 405,472 for Democrats), we get new totals of 46,839,002 votes for the Democrats and 50,114,006 for the Republicans - or a two-party percentage of 48.31% to 51.69%.
Nineteen districts, however, either had only one major party contesting the election or had two candidates from the same party contesting a run-off after a jungle primary. Ten of these were won by Republicans, while nine were won by Democrats. The full results are below, and removing these votes from the popular vote total gives an updated total of 45,693,092 votes for Democrats and 48,245,180 total votes for Republicans; or a two-party percentage of 48.64% vs 51.36%. Districts marked with an asterisk in the table below were completely uncontested.
As you mention, these results are not final as counting is still ongoing in some districts. California in particular has quite a low reporting percentage at the moment, so the number of votes for Democrats in uncontested districts is likely to increase.
District |
Republican Candidate(s) |
Democrat Candidate(s) |
AL-01 |
139,854 |
- |
AL-06 |
154,058 |
- |
AZ-08* |
185,214 |
- |
AZ-09* |
185,322 |
- |
CA-10 |
- |
147,821 |
CA-15 |
- |
117,917 |
CA-16 |
- |
171,697 |
CA-29 |
- |
76,650 |
CA-30 |
- |
138,008 |
CA-34 |
- |
75,565 |
CA-37 |
- |
83,827 |
FL-05* |
- |
- |
FL-06 |
226,140 |
- |
FL-18 |
167,215 |
- |
IL-07* |
- |
155,143 |
LA-04* |
- |
- |
LA-06 |
205,165 |
- |
MA-04* |
- |
141,315 |
ND-00 |
147,984 |
- |
NY-09 |
- |
111,162 |
NY-13* |
- |
109,014 |
PA-03 |
- |
223,263 |
PA-13* |
259,764 |
- |
PA-14* |
229,688 |
- |
SC-03* |
189,491 |
- |
SC-04* |
164,956 |
- |
SD-00 |
253,772 |
- |
TX-06* |
147,924 |
- |
TX-11* |
181,769 |
- |
TX-19 |
152,042 |
- |
TX-25* |
184,850 |
- |
TX-26 |
183,379 |
- |
TX-31* |
185,814 |
- |
WI-06* |
239,217 |
- |
WI-08 |
239,217 |
- |
Total |
4,022,835 |
1,551,382 |