Washington ? Dazed and confused. The biggest primary night of the season has the two parties struggling to figure out their next steps in an increasingly volatile election year.

House Republicans tried on Wednesday to explain their costly defeat in a special election in Pennsylvania, a contest they had hoped would launch them toward big gains in November’s midterm elections. President Barack Obama failed for a fifth time to push Democratic choices to victory, a troubling sign for the White House.

Despite the White House support, Sen. Blanche Lincoln was forced into a runoff with union-backed Lt. Gov. Bill Halter in Arkansas and is clinging to her political life. Arlen Specter saw his long Senate career end altogether with Joe Sestak’s nomination in Pennsylvania.

Tea party activists scored a big victory in Kentucky, rejecting Senate Minority Leader Mitch McConnell’s hand-picked GOP nominee — Trey Grayson — for the state’s other Senate seat in favor of political upstart Rand Paul.

In several states, voters flocked to self-described outsiders at a time when support for Congress is low, anger at Washington high and backing for Obama divided.

However, the themes that surfaced in Tuesday’s disparate primaries may tell little about the likely outcomes of upcoming primaries in other states, much less how the general election in some five months will play out. More clear is that this is shaping up to be a raucous campaign season, with colliding variables and a host of unknowns.

While public attention focused on the Senate races, party leaders eyed the Pennsylvania House result.

Rep. Eric Cantor, the No. 2 House Republican, predicted a GOP takeover of the House this fall, although he said the loss in Pennsylvania was “evidence of the fact that we have a lot of work to do and we can’t get ahead of ourselves.”

Countered Tim Kaine, the Democratic Party chairman: “The party’s failure to take a seat also shows that while conventional wisdom holds that this cycle will be tough for Democrats, the final chapter on this year’s elections is far from written.”

A Republican victory for that Pennsylvania House seat would have advanced the party’s claims that major gains are certain this fall, and a takeover of the House is possible — a narrative officials had hoped to reinforce this Saturday in a special election to fill out the term of former Rep. Neil Abercrombie of Hawaii.

In Hawaii, Republican Charles Djou runs ahead in the polls while two Democrats split a preponderance of their party’s vote. Despite efforts at diplomacy, neither former Rep. Ed Case nor Colleen Hanabusa has agreed to withdraw, and the Democratic Congressional Campaign Committee recently announced it was halting its activity in the race after spending more than $300,000.

But what does it all mean? It’s an unpredictable political environment in which Republicans will seek to take control of Congress this fall and Democrats will try to curtail losses. Some GOP gains are expected because Obama’s party is the one in power at a time when the economy continues to sputter and joblessness persists. Those economic issues are voters’ top concerns.

“The message clearly is that they’re tired of business as usual in Washington, regardless of party. … The people want new faces and new fresh ideas,” Massachusetts Sen. Scott Brown, who rode a wave of voter anger to office in January, said in an interview.