Washington — Democratic hopes for next year's congressional elections have risen with the mercury during these sultry August days. The decision by Paul Laxalt, general chairman of the Republican Party, to retire from the United States Senate has given Democrats both a morale boost and the possibility of winning his Nevada seat.
``It does make our job slightly more challenging,'' said Sen. John Heinz of Pennsylvania, chairman of the National Republican Senatorial Committee.
Not only is Senator Laxalt President Reagan's close personal friend and a direct link with the Senate, he is credited with single-handedly building up the GOP in his state. His seat ``changes from a sure Republican to, at best, a question mark,'' said David Johnson, executive director of the Democratic Senatorial Campaign Committee.
Democrats have long seen next year's elections as their best opportunity in a decade to wrest the Senate from Republican control.
With the Republicans holding a 53 to 47 majority in the upper chamber, the GOP has 22 seats up for reelection. Several are listed as vulnerable by both parties. Democrats have only 12 seats to defend, with most of them considered safe.
Charles E. Cook Jr., publisher of a political newsletter, said that the likelihood of a Democratic takeover has become ``not quite 50 to 50, but it's pretty close'' and listed Nevada as a ``tossup.''
To be sure, Democrats have also suffered from retirements. Senators Russell Long of Louisiana and Thomas F. Eagleton of Missouri will not run, leaving their states up for grabs. But overall, congressional Democrats see the Laxalt decision as only one of several encouraging developments.
As one Democratic campaign aide put it, the slogan six months ago was ``our party in demise, their party on the rise.'' Now, the tables have turned, he said.
Recently, the Democrats held on to a House seat in a special election in east Texas despite an all-out Republican effort to elect the first GOP congressman there since Reconstruction. The narrow victory for Democrat Jim Chapman does not end realignment toward the Republicans among voters in Dixie, but it has slowed it down and rejuvenated Democrats.
Issues are moving in a Democratic direction. The special election gave Democrats a place to test-fly some campaign themes, and they apparently took wing.
Social security, the Democrats' most enduring issue, has returned. They can now charge that the Republican Senate, in a celebrated vote last spring, tried to freeze payments for a year. Democrats can also remind voters of President Reagan's uneven history of support for that popular program.
Democrats also see the issue of foreign trade deficits as a vote-getter, since foreign competition is tied to the loss of manufacturing jobs. A Democratic survey showed trade to be a major factor in the Texas special election.
Lawmakers in farm states are now home hearing about the troubles facing agriculture at a time when the Reagan administration is pushing for more austerity in the farm program. In Washington, officials are bracing for a major farm credit crisis next winter.
Moreover, Democrats argue that the tide has turned on the military buildup, with the reports of Pentagon waste.
GOP campaign chairman Heinz yesterday acknowledged the challenges, but held that the issues are not clearly leaning toward Democrats.
``The key factor for 1986 is going to be the economy,'' said Senator Heinz. ``If we avoid dipping into an economic downturn, I think that'll be the most important help that our incumbents could have.''
He said, ``There's a general feeling that the White House has been asleep at the switch on trade issues.'' He said, however, that ``Senate Republicans are determined to take the initiative'' on trade, thus avoiding the blame.
The farm economy is ailing, ``yet there is frankly no sign that farmers are inclined to vote against Republican incumbents because of that problem,'' said Heinz. ``I see no member of the class of '86 who's in trouble with the farmers.''
During the next few weeks several major decisions are expected that will shape the 1986 elections.
The Laxalt retirement adds new importance to whether Sen. Charles McC. Mathias Jr. will run for re-election in Maryland. Without him, the GOP would almost certainly lose the seat. ``It's not what you would call a safe Republican state,'' understated Heinz of the heavily Democratic Maryland.
Senator Mathias has sent mixed signals but is expected to make up his mind by Labor Day.
Democratic Sen. Gary Hart of Colorado has not announced his intentions. In another race, Republicans say they are now confident that Sen. Jake Garn (R) of Utah will run.
A number of top challengers are expected to decide soon about whether to run in Oklahoma, Vermont, Washington state, North Dakota.