AH, THE SOLACE of a second debate: President Reagan now knows that his four-year string of verbal inanities isn't going to deflate his cozy 15-point advantage. This battle really is over. Hail to our doting, yet avuncular Chief.

Republicans have finally dusted, off that nuisance, Mondale, and they can now turn their attention elsewhere. And the result of this contest will, in all probability, determine the efficacy of Reagan's second administration. Most analysts believe that only the currently Democrat-controlled House of Representatives stands between the President and an effusive outpouring of conservative legislation.

The most salient question of the campaign now becomes, then: is this obstacle destructible? Can the Republicans regain control of the House?

The numbers suggest, quite emphatically, that they will not. In the House, Democrats powerfully outnumber Republicans 266 to 167. And no one is predicting that Republicans can mop up the 50 seats needed to compose a working majority.

For the days of F.D.R. and Truman are gone. In 1932, 97 freshmen rode in on Roosevelt's coattails, and in 1948, 75 Dems latched on to Truman's. But today, the powers of incumbency are too great; direct mailing and casework are simply too effective. In addition, ticket-splitting is increasingly in vogue among voters, and a Presidential ballot does not affect the Congressional one to the impressive degree that it once did.

But the 99-seat gap between the two parties is deceptive because it masks the Republicans' true brawn, for it does not account for the swarm of vouthern Democrats--most of whom are far more conservative than Republican moderates--which has undermined partisan solidarity within the House. Given the ideological similarity between these deviant Democrats and the GOP. Republican strategists would be as pleased as punch to nab just 25 to 30 seats on the other side of the aisle. Such a transfer of power, all agree, would greatly facilitate the initiation of Reagan's agenda, whatever that agenda turns out to be.

In fact, many pollsters and political consultants have been bold enough to predict a transfer of 25 to 30 seats to the Republicans. One Washington analyst even envisions a scenario in which the GOP could pick up 37 seats.

"The clues are there that would substantiate a claim for substantial Republican gains," says Charlie Cook, editor and publisher of the National Political Review.

Most of the factors contributing to the halycon Republican forcast are demographically oriented Presently, the electorate is undergoing powerful transformations, and these changes tend to bolster the GOP's political stamina

Nationwide, more and more voters are identifying themselves as Republican. According to Market Opinion Research, a Detroit-based polling firm, only a bare 46 percent plurality of the voters now (September 43-22, 1984) think of themselves as Democrats, as opposed to 45 percent Republicans. In September 1980, a more commanding 53 to 40 percent majority of the electorate identified itself as Democratic.

Additional polling information also indicates that the nameless Republican congressional candidate has grown significantly more attractive to the voters. Four years ago, a 50 to 39 percent majority of the voters went Democratic in the congressional elections. Today, while the liberals still hold a thin plurality, that margin has decreased from 11 to three points (47 to 44 percent). Moreover, in 1980, despite the generic Democratic candidate's advantage, the GOP nevertheless steamrolled its way to an over whelming 34 House seats.

And from July to September, Reagan's name increasingly carried more weight with the voters. Growing numbers of them who supported the nameless Democrat ironically declared that it's important to give Reagan the numbers he needs in Congress to push through his policies. Much of the electorate, then, is limp, easily swayed into joining the Republican camp when the President is mentioned.

Bad news from the pollsters? Well, there's more. The Republican National Congressional Committee claims to have rounded up more than two million new voters, enough to counter Jesse Jackson's registration efforts in the south.

And, there's a whole slew of weak Democrats drowning in strong Republican districts: New York's Stanley Lundine is said by many to be gone, and California Dem Jerry Patterson is having a hard time keeping his head above water. To this list add James McClure Clark, Don Albosta, Bob Carr, Tim Penny and Joe Minish. All of these Democrats are ideologically off base in their respective districts.

IS THERE ANY hope at all for liberals? Or will they spend the next four years worrying about further budget slashes and additional legislation that dicates the way to

Taken by itself, the above evidence would appear to justify a 30-seat swing. But the majority of analysts are forecasting shifts of only 12 to 18 seats. One determinant which serves somewhat to nullify the electorate's changing demographic nature is gerrymandering.

Most of the states with large populations--thus more congressmen--have Democratically-controlled state Houses and commissions. These bodies reconfigure districts, packing large numbers of Republicans into only a few C.D.s, and somewhat diminishing the potential impact of a Republican electorate. California's Democratically-controlled state legislature is notorious for its practice of altering the geography of particular districts when it thinks Republicans are growing too strong. A ballot proposal now seeks to put the gerrymandering process into the hands of a bipartisan, independent commission.

This year, there are fewer open seats up for grabs--only about 20--and this fact should benefit the Democrats, Normally, more than 40 districts do not have incumbents running, and these seats are usually more inclined to go to the victorious presidential candidate's party. So what could have been a source of strength for the GOP has been significantly diminished.

But most important, during the course of the campaign, President Reagan has failed to piece together a program for the future; he has not provided any new ideas. In short, he has failed to nationalize the election, to give it a country-wide dynamic which could cut across the idiosyncratic quirks of particular districts.

In 1980, Reagan seemed to say to the public: "In order to a) decrease taxes, b) cut spending, c) pump up the military and d) reduce the deficit, we need to elect Republicans. Democrats just haven't done the job." Such a campaign strategy gave the voters a reason for going with the Republicans; these nationally-voiced ideals supposedly led to the mandate--and a gain of 34 seats in the House of Representatives--which the voters dropped into the President's lap.

But-what has he said to the electorate this year? Practically nothing. He hasn't related a vision of the future as he did in 1980. This year, the people would be electing Republicans on blind faith, content to hang on to the status quo. The only purpose which might galvanize people to vote Republican is the prevention of a tax increase. But in fact, most voters are quite skeptical--given the size of the deficit--that Reagan in the end will be able fend off an imminent tax hike.

"There are no ideas out there." Washington Post editorial writer Michael Barone says. "That's gonna hurt a big Republican coattail, because large coattails come when the people have something substantative to vote for."

To WHAT EXTENT, then, have the Republicans succeeded in nationalizing the election so that voters see the campaign as a referendum on Ronald Reagan and his policies, rather than individual battles between Democrats and Republicans? Republican candidates everywhere have attempted to link Mondale and democratic congressional candidate X. The NRCC has splashed the tax issue across the television screens of America.

"But I don't think it's worked yet," one political consultant says. "Successful Presidential candidates gain a lot in Congress when an election is nationalized. But this year, things seem to be more localistic, way more so than in 1980. There's no message out there, and thus there's no real great overriding reason to vote Republican for the sake of just supporting Ronald Reagan."

Republican congressional candidates have been set adrift with nothing they can latch onto except a controversial party platform that serves only to alienate much of the electorate. That document has been abandoned by practically everyone, but there really isn't anything, except for the promise of on tax increases, to take its place. And the tax issue, with the looming deficit, isn't going to carry an entire party.

As a result of changing electoral democraphics and the President's personal popularity, the Republicans will pick up some seats--maybe 12 or 15. But such a number won't be enough to disturb the Democratic check on policy.

Reagan's "progressivity?" He's certainly not going to find it in the House.