For disaffected voters, another possible outlet

WASHINGTON -- Last week's flurry of speculation that Mayor Michael Bloomberg of New York City would run for president as an independent added to the sense around Washington that unexpected developments are destined to roil the current field of candidates.

Bloomberg, who raised many eyebrows by changing his registration from Republican to unaffiliated, disclaims any presidential ambitions. And there's some reason to believe that his carefully timed change of party registration was an ego-fueled bid for headlines and appreciation, rather than a presidential run.

But if Bloomberg were serious about running, he could find a niche. Voters are increasingly dissatisfied with their government, and there may not be enough outlets in the current field of candidates to channel their frustration.

In the latest NBC News/Wall Street Journal poll, voters gave shockingly low approval ratings to both President Bush (29 percent) and the Democratic-led Congress (23 percent). The great mystery in today's politics is how there could be so much dissatisfaction with so few outward signs of disturbance. Antiwar protests remain modest in size and temper; the only clamor for law and order on the right is directed at illegal immigrants.

The reason seems to be that while most people are dissatisfied, they have vastly different reasons for feeling that way. Therefore, there can be no single outlet for public dissatisfaction. No one savior can or will win over the disaffected masses.

Liberals who are passionately opposed to the Iraq war are dismayed that Democratic leaders in Congress haven't stopped the war, but they aren't about to turn to Republicans for answers. Some conservatives are angry at Bush for supporting the immigration bill and disappointed in his handling of a war that many still support, but they aren't moving to the left.

Within the two parties, the top candidates have been cautious in criticizing their current leaders. Republicans have tiptoed from Bush on some issues, but not on the biggest one -- the Iraq war. Most Democratic contenders opposed the decision of their party's congressional leaders to approve a bill to fund the war without a timetable for troop withdrawals -- but reserved most of their fire for Bush, not their congressional brethren.

There may be votes to be won on the political extremes, but the most viable candidates aren't willing to alienate moderates within their own parties to do so.

Some political observers have suggested that the current atmosphere is reminiscent of 1968, when the Vietnam War created dangerous political cross-currents: angry protesters on the left and furious law-and-order conservatives on the right.

Thankfully for the country, the historical parallel doesn't seem all that apt: The turmoil of 1968 has been unmatched in recent history. That year's presidential election featured an assassination, a dangerously demagogic third-party challenge, a Democratic convention nearly overrun by riots, and a photo-finish outcome that left bitterness in its wake. (The turbulent Nixon presidency was its result.)

Next year's race is unlikely to be another maelstrom. Still, the possibility that competing impulses in the electorate will lead to an unpredictable result seems real, suggesting that 2008 could be a quieter version of 1968.

So far, the presidential race has been quiet to the point of boredom, at least in terms of memorable pronouncements and vivid disagreements. But the Iraq debate will heat up again in September, when General David Petraeus reports to Congress on the effectiveness of the troop "surge," and the presidential primaries will occur in the midst of more legislative skirmishing over war funding. Then, perhaps, the volume will increase.

How Bloomberg, who made billions of dollars selling online business news, would fit in is unclear. He's not a fiery extremist like George Wallace, the former Alabama governor who was the third-party candidate of 1968. He's more like Ross Perot without the nutty expressions: He promises a responsible, centrist businessman's approach to running the government.

Other candidates, such as Bloomberg's mayoral predecessor Rudy Giuliani, former Massachusetts governor Mitt Romney, and many Democrats, are offering their own messages of competence-not-ideology.

So it's likely that both parties will end up with nominees who contend that they could run the White House more smoothly than Bush.

If he hopes to stand out as a moderate, Bloomberg would have to craft a centrist approach to the war on terrorism.

It's hard to imagine what such a thing would look like, but it probably would get a good hearing from a dissatisfied public. At this moment, the status quo in both parties is unacceptable to most voters.

Peter S. Canellos is the Globe's Washington bureau chief. National Perspective is his weekly analysis of events in the capital and beyond.