When Virginia's Republican governor, John N. Dalton, vetoed a bill last week that would have put party labels beside candidates' names on election ballots, it was not much of a surprise.

However, his stated reasons for killing the bill merit notice. Dalton is viewed, especially by Democratic leaders of the General Assembly, as a partisan governor, a thoroughgoing Republican intent on using his office when possible to build the GOP in Virginia.

From such a partisan, his brief statement explaining his veto of the party designation bill accorded very little value to party affiliation.

"The (party) label cannot hope to encompass the great variety of things that go to make a good public official," he said. "A party label is not as important as the candidates' character, capacity, philosophy or leadership."

Possibly no one ever looks to party affiliation as an indicator of "character, capacity and leadership," but philosophy" is something else. A philosophy of government is something that can be translated into executive proposals and legislative policy.

Differences over philosophy of government form the basis for grouping into political parties, but the Dalton statement implies that party affiliation is irrelavant to the philosophy of candidates in Virginia.

It is a little surprising that he said it, but very difficult to argue with his conclusion. Neither the Republican nor Democratic party of Virginia has taken positions on controversial issues in the state in recent years and there is no move afoot to do so.

The Republicans have become a club for organizing the executive branch and the Democrats a club for organizing the legislative branch. You can pick your club. Membership is open. You don't have to believe in anything in particular to join.

Given this state of affairs, party labels, as Dalton suggested, are not much of a guide. A Democrat in Martinsville who has been voting for House of Delegates Majority Leader A. L. Philpott every two years could hardly be expected to move to Arlington, Alexandria or Fairfax County and vote for the Democratic House incumbents there on the assumption that they share a common view on important issues with Philpott. Sometimes they do. Very often they do not.

A search for common ground among party candidates on national issues is equally fruitless. Among the Democratic candidates for the U.S. Senate nomination, such party regulars as Andrew Miller, Carrington Williams and Rufus Phillips often appear to be running against the policies of the Carter administration and Democratic. Congress as ardently as the Republicans.

If the Republicans in the General Assembly appear to be more cohesive in philosophy, it is only because their small numbers limit the possibilities for variety of thinking.

The question is, then, why should the state government take any action to focus voter attention on anything as irrelevant as the party identification of the candidates?

The parties have no constitutional or statutory role in the government. Their activiites are regulated by law, but the law created nothing for them to do that warrants official government labeling on ballots.

Some argue that parties have become such well established institutions in our system that the government should follow a policy of strengthening their role. If that is true, then the best place to start would be with registration of voters by party or as non-partisans. That would provide a more accurate measure of party importance and protect the integrity of party primaries.

As it is now, anyone - Republican, Democrat, Independent - can vote in a party primary in Virginia. It is patently illogical to label candidated in a general election as the representative of any one party if they have been chosen in a primary that included members of the other major party or no party at all. That is exactly what would happen if Virginia adopted party designation on general election ballots without first requiring registration by party.

There are many Democrats who doubt, probably with good reason, that John Dalton spent much time pondering the role of parties in our system of government before vetoing the ballot label bill. They believe vetoing the ballot label bill. They believe he was more worried about the electoral fortunes of conservative Republicans who are making inroads into a conservative electorate that he and other Republicans are trying to wean from the habit of voting Democratic.

If that is the case, his public reasons for the veto are better than his private ones. Whatever his reasoning, the veto itself is a logical one.