Analilia Mejia, a progressive Democrat, is competing on Thursday in New Jersey against Joe Hathaway, a Republican who has tried to distance himself from President Trump.
An effort to privatize the facility is a key test of whether Kyiv can overcome concerns about Russian attacks and corruption to attract foreign investment.
Democrats in key Senate races out-raised their Republican rivals, but super PACs on the right are poised to play a powerful role in the midterms, new campaign finance filings showed.
The vice president is also the finance chair of the Republican National Committee, allowing him to court donors who could prove helpful should he run for president.