( CNN ) -- Voter turnout was terrible last Tuesday . As President Barack Obama lamented in his post-election press conference Wednesday , two-thirds of voters chose not to vote , making it perhaps the lowest midterm turnout since the 1940s . Conventional wisdom says low turnout favors Republicans , and it did last week . But the days when one party sees low turnout as being in its own interest might be drawing to a close -- and it may be Republicans who will drive the change . First , some context . Midterm electorates are typically smaller , whiter and older than presidential electorates . In recent years , the GOP has worked hard to ensure that its shrinking , white , aging base turns out in disproportionately large numbers . And even though there are plenty of Republican leaders who 'd like to see their party become younger and more diverse , the practical pressures of here-and-now politics have led them to go into campaigns with the voters they have , not the ones they wished they had . But on Tuesday , the wishes of those Republicans hoping to expand the base started coming true -- at least on the margins , and enough to suggest a new way forward . While Republicans extended their dominance among older white voters , they also made modest inroads with Latino and Asian-American voters , partly by downplaying the nativist messages of past cycles and partly by exploiting frustration with the Obama administration . Several new-generation black , Hispanic and Asian Republican candidates were also elected across the country . Meanwhile , GOP leaders such as Sen. Rand Paul have been engaging millennial voters on campuses and elsewhere with an unapologetic libertarianism that resonates with some young people . As a result , it 's possible for a smart Republican to see 2014 not only as a win , but as a hint of how the party could prevail in 2016 as well . To put it simply , the GOP might soon see it as in its own interest to boost turnout among young voters and voters of color , instead of writing them off or , as still happens too often , blocking them from voting at all . This would be a major departure , to be sure . We 're still a long way from a heartfelt and well-executed effort to expand the GOP demographic base . And even if party leaders want it , there are still too many voters who vote Republican precisely because they fear or blame the very people the leaders want to bring into the tent . Still , it 's at least becoming possible now . There is an opening among Latino , Asian and young voters . And it would be fantastic for the country if Republicans pushed to exploit that opening . That may sound funny coming from a Democrat . My party in the 21st century has become the default choice for voters shorthanded as the `` rising American electorate , '' which is to say , young and nonwhite voters . I recognize that an effort by the GOP to grab a chunk of that electorate would be a challenge to my party . As an American though , I 'd love to see it happen . I 'd love to see young and nonwhite voters tell candidates from both parties that they are not to be taken for granted , and I 'd love for each party to try to outdo the other not just in raising money but in raising turnout across the board . It would be great for the country if both parties in earnest developed new policy ideas that address the hopes and dreams of millennial voters and voters of color . This means not simply trying to win by carving off slightly more than half of those voters that do turn out , but trying to build true majorities of all the voters . Weeks before the midterm elections , Rock the Vote released a video that went instantly viral called `` Turn Out for What ? '' With rap stars and other celebrities , it drove home the message that there were numerous issues , from same-sex marriage to marijuana to student debt , that should drive young people to turn out and vote . In the end , of course , only a fraction of them did . `` Turn out for what ? '' can be also read as a cynical statement . As in , `` Why bother ? '' If we 're ever going to change the `` Why bother '' attitude , it 's going to be because both parties are actively fighting for voters not just in their currently defined bases , but in every subgroup . So I hope , for my country , that the party I do n't belong to starts investing heavily in appealing to people who do n't belong to it either . And I hope , for my country , that members of this rising American electorate start demanding more from both parties before giving away their votes , either by casting predictable ballots or not casting them at all . I loved the Rock the Vote campaign . But true progress will come when we wo n't need chiding , even fun chiding , to get out and participate , when both parties will be outracing each other to bring more people into the voting booth because they 'll have nothing to fear from elections that are truly representative . Let 's turn out for that .
Midterm voter turnout last week perhaps was lowest since 1940s . Comment: To beat voter apathy , parties must compete for voters in all groups , Liu says .