RICHMOND -- State Sen. Wiley F. Mitchell Jr. (R-Alexandria) had his blood pressure checked on Day 2 of the legislature last week and found it had shot up a whopping 40 points above normal.

Mitchell, who has a sense of humor about such things, conceded that the blip may have had something to do with his blistering attack the day before on Gov. Gerald L. Baliles' record state budget. But other longtime watchers of the genial North Carolina native say he's afflicted by a more serious malady: He's running this year for one, and possibly two political offices that open up in 1989.

Mitchell, of course, is not the only victim of the syndrome that turns several of Virginia's 140 state lawmakers into crusaders and preachers when the General Assembly convenes every January. The weeks of uninterrupted media scrutiny, the regular stroking by dozens of lobbyists and a grab bag of volatile issues are catnip for these publicity-conscious pols.

Still, this long budget session, dominated as it is by the governor's spending plan and spiced with a number of other issues, promises more jockeying than usual. To an ambitious Democrat or Republican in the legislature, the 21 1/2 months between now and the statewide elections of 1989 constitute the blink of an eye. The theory is: Collect those political IOUs now, for cashing in next year.

Therefore, the game of matching legislators to the higher offices they covet has begun in earnest. Mitchell would dearly love to be governor, but privately acknowledges that he may be too liberal for his party and may have to settle for attorney general. If so, he would be joining an already crowded field, but more on that later.

Senate freshman Edwina P. Dalton, the widow of former GOP governor John N. Dalton, is already under considerable pressure from some in her party to run for lieutenant governor, despite her avowed intention to complete her four-year term. Dalton, who will be watched closely this session by Republicans and Democrats alike, has proved her vote-getting ability despite a somewhat cloying rhetorical style; for instance, the text of the swearing-in speech issued by her office began with the line, "Wow! What a crowd!"

There seems to be no shortage of Republicans in the House of Delegates with their eyes on higher office. Del. Raymond R. (Andy) Guest (R-Warren), the minority leader, has taken to hosting coffees for reporters -- he calls them "Can we talk" sessions -- to boost his nascent campaign for governor. Meanwhile, Del. Arthur R. (Pete) Giesen Jr. of Waynesboro, who frequently jostles with Guest for the limelight, is off and running for lieutenant governor, as is Del. Frank D. Hargrove of Glen Allen.

G. Steven Agee, a GOP delegate from Roanoke, would like to win his party's nomination for attorney general, a post once held by his lookalike first cousin, Gov. Baliles. Also contemplating a bid for the state's top law enforcement post is Republican Sen. Joseph B. Benedetti, a Richmond lawyer, according to GOP activists.

On the other side of the political aisle, Democrats are mentioning state Sen. Joseph V. Gartlan Jr. of Fairfax County for lieutenant governor, a job Gartlan emphatically says he has no interest in seeking.

Among House Democrats, Del. V. Thomas Forehand Jr. of Chesapeake has scheduled a major fund-raiser for April 5 that is likely to draw the governor and luminaries from the business community here and in Tidewater. Depending on whom one talks to, Forehand is running for attorney general, lieutenant governor, Congress or all three. The delegate himself says he will seek reelection in 1989.

Del. John G. (Chip) Dicks III, a suburban Richmond lawyer, also has been mentioned for attorney general, though his relatively young age, 36, could be a handicap.

Of course, all these personal agendas hinge a great deal on what the superpowers of the two major parties decide to do. On the Republican side, Mitchell is now gently beating the bushes on behalf of retiring Sen. Paul S. Trible Jr., who is considering a gubernatorial bid. Former state attorney general J. Marshall Coleman is actively working on the GOP's nomination for governor.

Among the Democrats, state Attorney General Mary Sue Terry has yet to announce whether she will seek the nomination for governor against Lt. Gov. L. Douglas Wilder, who is holding a star-studded fund-raiser here on Saturday to build a head of steam behind his own campaign.

As Mitchell put it, "There are a lot of us here who are waiting for the dust to settle. All I've done so far is refuse to make commitments. We all want a clearer picture of what's going on."