Once you understand that Ronald Reagan has a lock on Indiana's 11 Electoral College votes, a bleak cameo of 1980 politics, congressional-style, emerges from the fustian.

It's nasty, partisan and distorted; outsiders are running amok with their big money; a couple of the Democratic Party's household names are in a heap of trouble.

And if you think anyone's debating such issues as the world detonating itself or kindred trifles, forget it. In a year of anti-incumbent fervor, with state unemployment at 12 percent, the issue here is the economy, who's to blame, what's to be done.

The most sparks are coming from the fight between Democratic Sen. Birch Bayh, seeking a fourth term, and Republican J. Danforth (Dan) Quayle, a two-term congressman who, at 33, bills himself as "the hope of the future" and seems to believe it.

The race is neck-and-neck, by all indications -- typical for the liberal Bayh, who never has won more than 52 percent in this generally conservative state. By the time they're finished, Bayh and Quayle will have spent an estimated $4 million in a race that has riveted the attention of ideologues, left and right, all over the country.

But there are other acts in the Hosier circus. For example:

Rep. John Brademas, the No. 3 Democrat in the House, is under unexpectedly intense pressure from an unknown young real estate man, John P. Hiler, in his quest for a 12th term representing the South Bend area. Polls indicate a cliffhanger, although Brademas has accelerated his campaigning and fund raising.

In a particularly bitter race, deemed too close to call, Rep. David Evans, an Indianapolis Democrat, is matched for a third time against conservative David Crane, brother of the two Illinois Republican congressmen Philip and Dan. Crane's misstatements of Evans' voting record has led to Evans' radio jingles that in effect call Crane a liar.

Incumbents elsewhere appear to be in better shape, but there are quirks. GOP Rep. John T. Myers from the 7th district, refusing to debate his opponent, Patrick Carroll, is videotaped in flight down a Bloomington alley to avoid a face-to-face meeting. Rep. Andy Jacobs Jr., a penny-pinching Indianapolis Democrat, in a tight race with lawyer Sheila Suess, runs his campaign from a nephew's apartment with a telephone only recently hooked up.

The question, of course, is how the commanding 2-to-1 leads of Reagan for the presidency and Lt. Gov. Robert Orr, a Republican, for the governorship, may provide coattails for GOP challenges to seven Democratic congressional incumbents.

The question looms largest in the Senate race, in which Bayh, 52, master of campaign folksiness, is seeking to become the first Hoosier ever elected to a fourth term.

Bayh's liberal voting record makes the New Right see red and has earned him a high priority on the conservatives' national hit list. Although Quayle has renounced the help, saying it only stirs sympathy for Bayh, New Right groups have poured an estimated $500,000 or more into Indiana.

"It's been vitriolic . . . traditional Republican rhetoric. And the outsiders have come in here in force," Bayh said the other day. "They don't care what the truth is -- the distortions are flagrant."

Quayle's concern about a pro-Bayh backlash may have merit. When the Indianapolis Star banner headlined a poll this week showing Quayle 15 points ahead -- a surprise finding that even Quayle distrusted -- Bayh got $5,000 in unsolicited telephone contributions. Reporters in Valparaiso the next day gave Quayle an uncustomary working over.

"No question, the poll has actually helped us," Fred Nation, a Bayh aide, said today. "It got our people moving, activated them. And we think the press will now look at Quayle more closely."

As always, the press is a big factor again this year. The Star is the flagship of the Pulliam chain, fervently conservative papers that have about a fourth of the state's daily circulation. Quayle is an heir to a share of the Pulliam empire, was associate publisher of the paper at Huntington and was promised the Star's endorsement a year ago.

That aside, the choices seem fairly clear, for Bayh and Quayle agree on virtually nothing. With some irony, Quayle told an audience at Crown Point this week that the only thing he agreed on with Bayh was his campaign theme of 18 years ago that three terms are too many for a U.S. senator.

That was 1962, when Bayh upset an entrenched Homer Capehart in a race somewhat akin to this one -- a young upstart challenger, arguing that it's time for a change, nipping at a three-term veteran.

Quayle's message -- the same at all his stops in a peripatetic campaign that he began in March 1979 -- seems to play well most places, but there are complications. Bayh is answering the negatives with negatives of his own, and on that score, Quayle has not come off so well.

When Quayle talked about protecting Indiana industry from foreign imports, Bayh noted how the Fort Wayne Republican opposed his legislation to require the use of American products (such as Indiana steel) in transportation projects involving federal money.

When Quayle said, during one of their few head-to-head debates, that he would have to study fair housing legislation before taking a stand, Bayh drolly reported that Quayle already had voted against it in the House.

Quayle's denials that he has taken money from oil industry political action committees have been parried by Bayh with records showing the opposite and a tough commercial about "dirty hands." Quayle's claim to being an inflation fighter is countered by Bayh noting that his opponent voted for oil decontrol.

Such gaffes have not gone unnoticed by Hoosiers, who, even though they may be Republicans, acknowledge that Bayh is one of the most skilled campaigners in the state's history.

For months before the fall campaign got rolling, Bayh was announcing the grants and project approvals he was winning for Indiana back in Washington.

For all the clamor about Bayh being "anti-gun," for his efforts to ban Saturday Night Specials, the senator recently wheeled out a letter from the National Rifle Association calling him a "friend of gun owners."

For every question raised by Quayle, Bayh has a riposte. "I've made some mistakes," Bayh told students at Indiana University the other evening, "but you can choose between two incumbents . . . Dan Quayle is very nice, very articulate, but in four years he hasn't passed a bill, hasn't put a single bureaucrat in his place, hasn't cut a single tax. I don't think a fellow like that needs a promotion."

A day later, at Valparaiso, in the key Lake-Porter county northwest corner of the state, where he has campaigned repeatedly, Quayle was encountering some problems of his own.

Upstairs in the board room, where executives embraced him, Quayle was a hit at the McGill bearing factory. Outside, at the plant gate, it was a bit cooler. A young black worker coming off shift said thanks, but no thanks, Bayh was his man.

A chubby young woman trundled past in the cold, refusing Quayle's outstretched hand. "I don't vote," she said.

"Whaaat? Why not?" Quayle called out.

"You're all crooks," she answered.