. >>> the system is designed to reduce participatesonship. in the race for senate, 23 candidates challenging dianne feinstein. he feels voters will be left out. >> for the republican voters who want to express their views in support of a conservative candidate that choice will no longer be there. >> you could see maybe the more very partisan members get a real challenge. they won't be a shoe in anymore. >> reporter: california voters approved approved the new system two years ago and it would be up to the voters to change it back. rob roth, ktvu channel 2 news. >>> more details now, voters in san francisco can vote early from 8:00 a.m. to 5:00 p.m. monday through friday. it would be closed on may 28 for memorial day and today they sent out vote by mail ballot and already begun bailing pamphlets to voters. >>> twitter is expected to become a key tool as the election kicks into high gear. in the last election twitter was still new. now twitter gets tweets and they could be effective in getting a message across. >>> no word on whether scott thom