Three political party leaders had a reason to smile to the television cameras last Sunday as votes came in for the Tokyo legislative election. Of course, they included the leaders of the Liberal Democratic Party (LDP) and its partner Komeito. After all, together they had just won a landslide victory.

But also beaming to the cameras before a background of little red roses attached to the names of its winning candidates was Kazuo Shii, the longtime leader of the Japanese Communist Party (JCP). His party had more than doubled its strength in the legislative assembly.

Astonishingly it won more seats - 17 versus 15 - than the Democratic Party of Japan (DPJ), which not only had controlled the Tokyo assembly before the election but also formed the government of Japan until about six months ago.

Elections to the Tokyo Assembly are often bellwethers to national elections. The success of the Democrats in the 2009 legislative election presaged its smashing victory one month later. Similarly, the governing party's triumph in this election bodes well for its success in the House of Councillors election in July.

Prime Minister Shinzo Abe had very good reason to be cheered - his party and his electoral partner won every seat they contested - and to interpret it as an endorsement of his economic policies, dubbed "Abenomics" even though little has yet trickled down to ordinary people.

After six months in office, the Abe government continues to hold popular approval ratings in the 60 percent range. This is almost unprecedented for recent Japanese governments. The main reason for this is general approval of Abe's economic policies. The average person may not know exactly what "quantitative easing" is, but for the moment likes the idea that the government is doing something bold to attempt to fix the economy.

Of course, the Abe government has had pretty much of a free rein during its early months in office due to the almost total lack of any effective opposition. The DPJ, which should provide that kind of opposition, has been virtually invisible these past few months and is, anyway, still too toxic with the voters.

The new Japan Restoration Party, led by Osaka Mayor Toru Hashimoto and former Tokyo governor Shintaro Ishihara, may be the third-largest bloc in the parliament. But the restoration party is also floundering, due in part to the mayor's controversial remarks on comfort women. It did poorly in the Tokyo election, losing one of its three seats.

Enter the communists. During the election, the JCP campaigned as the "only true opposition party." It succeeded in making itself the receptacle for many anti-LDP voters, who had given up on the democrats. Said its leader Shii: "it is important to take on the LDP and offer an alternative."

But are the communists a viable and reliable vessel for the anti-Abe vote? After all, the party won only eight seats in last year's general election to the 480-seat House of Representatives, an awfully small base from which to build. It was the party's poorest showing in 45 years.

The JCP's declining fortunes have in some respects been linked to the democrats. As the main opposition party rose in popularity the communists seemed to recede. Now the shoe is on the other foot. The democrat's fortunes are plunging and those of the communists are rising.

Japan's communists have always had two things going for them: persistence and constancy. Few political parties anywhere have put in so much effort into winning so few votes. In this month's election large, expensive sound trucks harangued commuters to vote for them at railway stations.

The JCP is the only political party in Japan that fields candidates in national elections in every one of the 300 electoral districts (the other parties, including LDP make deals with likeminded parties). It must cost the party a fortune in lost deposits.

Moreover, the JCP has traditionally championed just a few key issues, such as opposition to the Japan-US Security Treaty and protection for the country's pacifist constitution. It was anti-nuclear power even before the massive Fukushima earthquake, an issue in which it is basically in tune with a majority of Japanese.

Of course, the Communists can be expected to criticize the government's economic policies as they unfold over the next few months, as benefitting the rich but not trickling down to the average worker. That may strike a chord if, in fact, Abenomics does not work as well as the government hopes it will.

But can something called the communist party (the common production party in literal translation) really become the viable opposition? Can it fill the role that the now defunct Japan Socialist Party provided for years? The socialists won many more seats (though never enough to form a government on its own) than the JCP ever did.

The overarching theme of Japanese politics for the past 20 years has been a search for a viable, non-Marxist opposition party that the public could trust with the reins of government. These elements eventually coalesced into the Democratic Party of Japan, which abandoned such electoral baggage as opposition to the self-defense forces and the security treaty.

Eventually it achieved its historic mission of removing the LDP from 50 years of nearly uninterrupted power, only to find itself beaten and virtually persona non grata in its own country.

The coming months will provide plenty of issues to challenge the Abe government from a center-left perspective. They include Abe's desire to boost the status of the self-defense forces, revive nuclear power and rewrite the American-written constitution.

It is hard to see the democrats becoming such an effective opposition anytime soon. It seems equally unlikely that even those in the Japanese public that oppose such conservative initiatives will turn whole-heartedly to the communists. But if not them, then who?