It hasn't been a good season for House Republicans. On the issue they made the biggest noise about -- the contest over the Indiana 8th Congressional District -- they lost and have seen the issue die. It will be helpful for them in 1986 in exactly one of the 435 districts. They've had a few victories; they had the satisfaction of seeing many Democrats scamper back, after Daniel Ortega's trip to Moscow, to put through Minority Leader Robert Michel's Nicaraguan contra aid. But on most issues the House Republicans have not only lost; they have not even been consulted. In a town where everyone keeps score, the House Republicans are not even players.

That's not just because they're outnumbered by a generally unified Democratic caucus. They are also languishing because of their own mistakes.

A major misjudgment was on the Indiana 8th. Their position on the merits -- calling for a new election -- was right, because the result hinged on the validity of individual ballots on which reasonable people could disagree. But the Republicans were wrong to suggest, as many did, that this was just one example of how Democrats were clinging illegitimately to control. They had a sense -- based on misleading election-night statistic -- that Republicans had won more House votes than Democrats and had fewer House seats only because of gerrymandering. In fact, Democrats won 52 percent and Republicans only 47 percent of the vote for House seats last fall. Historically, those percentages have usually translated into about the edge in seats the Democrats have now. The shrillness of the GOP case on Indiana 8th ultimately rang false, because it was based on a false premise.

The other mistake the Republicans have made is to abandon the assaults some of them, notably Newt Gingrich, were making on the opposition on substantive issues in 1983 and 1984. This year House Republicans have contributed nothing of note to the budget debate. Aside from Jack Kemp, they've had little to say on tax reform. The review of foreign and defense policy urged by Republicans such as Mr. Gingrich has been delivered mostly by Democrats such as Armed Services chairman Les Aspin and foreign Affairs member Stephen Solarz. The House Republicans have lost the intellectual initiative.

They also seem to be losing some morale. Several competent senior members, who would have been key chairmen in a Republican House, have announced they're retiring, most recently Maryland's Majorie Holt. Almost everybody now expects the Republicans to lose at least a few House seats in 1986, and no one expects them to win control. That may not be surprising. What is surprising is that the House Republicans seem to have lost the vitality and originality that, before this spring, made them a distinctive and consequential part of political Washington.