Was this election rigged?

Flatland County has only two towns within its boundary.  Smallville has 400 voters, 100 of whom are Democrats and 300 whom are Republicans .  Bigville has 500 voters, 400 of whom are Democrats and 100 are Republicans.  Every voter votes a straight party ticket for his or her party.  The election this year is for county commissioner.

It’s election day. Smallville votes by machines and the votes are tabulated within one hour of the closing of the polls.  Results as of 10 p.m. on election day:

Dem county commissioner candidate–100 votes

Rep. county commissioner candidate–300 votes

Bigville voters vote by mail.  All the votes are mailed in a timely fashion and are received by election day.  The 500 ballots are then opened and counted.  The counting is complete at noon on the day following the election with these results:

Dem. county commissioner candidate–400 votes

Rep. county commissioner candidate–100 votes

The Democratic candidate now pulls ahead.  She has 500 total votes in Flatland County.  The Republican candidate has 400 votes.  

If this is like the mayoral election in Los Angeles or any election which involves Trump, Trump followers, MAGA candidates, or any other observer who lacks rudimentary knowledge of arithmetic, you will hear the cry “the election was rigged.”  They are that stupid.