(Portland, OR) -- Those wishing to vote in today's primary election need to submit ballots by eight o'clock tonight. Multnomah County elections officials are expecting a high participation rate this time, even though only 25-percent of ballots had been turned in by last Friday. Tim Scott with the Multnomah County Election Division tells KATU-TV that the presidential primary election, the Portland mayor's race and the gas tax could drive an increase in the turnout.