Following is a state-by-state roundup of the East (numbers in parentheses are Electoral College votes): Connecticut (8)

Democratic presidential nominee Walter F. Mondale has not been back here since Sen. Gary Hart (D-Colo.) trounced him in the March Democratic primary, and polls say he might as well not bother. President Reagan's margin in The Hartford Courant and other polls is more than 20 percentage points.

On paper, the closest House race should be the rematch between freshman Rep. Bruce A. Morrison (D) and former congressman Lawrence J. DeNardis (R). Morrison won by less than 2,000 votes last time and DeNardis never stopped running. But Morrison is also an indefatigable campaigner, and has been leading in both parties' polls.

Vice President Bush campaigned yesterday in New Haven, but coattails may be more important in the neighboring district, where Rep. William R. Ratchford (D) faces state Rep. John G. Rowland (R), who hails from Waterbury, the district's largest city and the site of a Reagan visit last month.

Ratchford is worried enough about the race to bring Democratic vice-presidential nominee Geraldine A. Ferraro in today. These are two races to watch for early indications Tuesday night of coattails. District of Columbia (3)

Unfortunately for Mondale, the country is out of step with its national capital this year. President Jimmy Carter carried the District with 75 percent of the vote in 1980. A Democratic sweep is expected, as in every election since the District gained the vote, carrying both Mondale and Delegate Walter E. Fauntroy (D). Delaware (3)

Delaware voters do two things well: They split tickets and back presidential winners -- eight elections in a row, a longer streak than any other state. This year they are leaning toward Reagan, by 23 points according to the Delaware chapter of the American Statistical Association's poll released last Tuesday. They like Sen. Joseph R. Biden Jr. (D) for a third term over former state House majority leader John M. Burris by 20 points.

Gov. Pierre S. (Pete) du Pont IV (R), retiring after two terms, passed up a chance to challenge Biden, but the popularity of his administration is helping Lt. Gov. Michael N. Castle (R), who holds a 14-point lead over former state supreme court justice William T. Quillen (D) in the polite gubernatorial race.

The House battle has been anything but polite, as du Pont's wife, Elise, a former Agency for International Development official, has gone from cozy "home-visit" campaigning to free-swinging television ad attacks on freshman Rep. Thomas R. Carper (D), who has been endorsed by the state's two major newspapers. The ASA poll had them tied, but private polls give Carper a slight lead. Maine (4)

Republicans have struggled to win Maine in recent presidential elections, but Reagan has been running far ahead this year, thanks in part to his support from the growing number of young people moving into the state. Sen. William S. Cohen (R) is cruising to a second term over state House Majority Leader Elizabeth H. Mitchell (D), whose support of a nuclear freeze boomeranged when she had to apologize for a personal attack on Cohen by freeze proponent Dr. Helen Caldicott. Freshman Rep. John R. (Jock) McKernan, Jr. (R) appears to be fighting off a vigorous challenge from former Democratic state chairman Barry J. Hobbins. Maryland (10)

It speaks volumes that Maryland, one of six Carter states in 1976 and a state whose Democratic leaders and voters gave strong early support to Mondale, is so shaky that both Mondale and Ferraro scheduled campaign visits in the final week. Polls have shown Reagan 9 to 13 points ahead, but history and a potentially big black vote keep the GOP from claiming it.

Democratic voter turnout efforts have not slackened, and the Free State could buck the national tide. Despite Reagan coattails in Baltimore County, Rep. Clarence D. Long (D) is a slight favorite to defeat former Federal Maritime Commission chairman Helen Delich Bentley (R) for the third time in their continuing grudge battle. Massachusetts (13)

People were shocked when Reagan won "liberal" Massachusetts in 1980 and said it was because independent presidential candidate John B. Anderson "siphoned off" close to 400,000 votes. This year, despite indications of a late Democratic "homecoming," Reagan is ahead again, this time in a two-man race. The Boston Globe poll had his margin at 10 points; private polls show it closer.

Although the GOP is talking upset possibilities, tradition is likely to prevail in the Senate race, where Lt. Gov. John F. Kerry (D), who came to prominence in the early 1970s as an antiwar Vietnam veteran, leads conservative businessman Raymond Shamie (R), by 13 points in the Globe survey.

Democrats feared Shamie might capitalize on his upset primary victory over former U.S. attorney general Elliot L. Richardson (R), but disclosures of his past ties with the John Birch Society have slowed him. The two candidates are competing for the seat of retiring Sen. Paul E. Tsongas (D).

In the most publicized House contest, Rep. Gerry E. Studds (D), censured by the House for a homosexual affair with a congressional page, has used his strong organization and service reputation to make himself the clear favorite over Lewis Crampton (R), a former Environment Protection Agency official. In the district Rep. James M. Shannon vacated to seek the Democratic Senate nomination, state Sen. Chester G. Atkins (D) appears likely to fend off the anti-tax-hike coattail campaign of attorney Gregory S. Hyatt (R). New Hampshire (4)

Reagan is running 2 to 1 ahead of Mondale in the polls and Gov. John H. Sununu (R) is almost as far in front of state House Minority Leader Chris Spirou (D) in his race for a second term.

The Senate race has been tougher and looks closer, with Sen. Gordon J. Humphrey (R) running about 10 points ahead of Rep. Norman E. D'Amours (D) in the latest WMUR-TV-University of New Hampshire poll.

The GOP counts the House seat D'Amours is vacating as one of its likeliest pickups, with third-time candidate Robert C. Smith (R) in front of state executive councilor Dudley Dudley (D), a liberal activist whose role in past presidential primaries has made her one of the best-known women politicians in the country. New Jersey (16)

It looks like a typical ticket-splitting, pro-incumbent year in New Jersey. Reagan has been cruising comfortably ahead of Mondale from the start and has a comfortable lead in the latest Washington Post-ABC survey.

Sen. Bill Bradley (D) has a landslide victory coming for a second term over Montclair Mayor Mary V. Mochary (R), which clearly will add to speculation about his potential for national office.

In the key House race, redistricting has moved 11-term Rep. Joseph G. Minish (D) away from his Newark suburban base and out into Morris County, where voting patterns favor state Assembly Minority Leader Dean A. Gallo (R). Minish, who had been written off earlier, is fighting back, but the GOP confidently calls this district a pickup. State Sen. H. James Saxton (R) should succeed the late Rep. Edwin B. Forsythe (R). New York (36)

Despite the help of the New York City duo, Ferraro and Democratic National Convention keynote speaker Gov. Mario M. Cuomo (D), Mondale has been struggling to overcome Reagan's steady lead. He still trails the president, 49 to 43 percent in the latest Post-ABC poll and private polls show Mondale close enough that the planned voter turnout program could put him over.

There are five hot House races, with three Democratic and two Republican seats at risk.

Long Island freshman Rep. Robert J. Mrazek (D) is favored to withstand millionaire investor Robert P. Quinn (R), and in another coattail district, veteran Rep. Stan Lundine (D) may hold a slight edge over Jill Houghton Emery (R), who did so well campaigning for her politician husband she decided to run herself. In the Westchester district of retiring Rep. Richard L. Ottinger (D), his former aide, Oren J. Teicher (D) is a bit of an underdog against accountant Joseph J. DioGuardi (R).

In the millionaires' battle on Manhattan's East Side, Rep. Bill Green (R) has no clear edge over borough President Andrew J. Stein (D) despite The New York Times endorsement. On Long Island, Rep. William Carney (R) had a tough primary and is being hard-pressed by assemblyman George J. Hochbrueckner (D), a vocal opponent of the Shoreham nuclear plant.

City Councilman Thomas J. Manton (D) inherits Ferraro's House seat and former state senator Fred J. Eckert (R) steps into the large shoes of retiring Rep. Barber B. Conable Jr. (R), unless the form sheet is crazy. Pennsylvania (25)

Republicans long have warned that this state, with its big Democratic registration edge and continuing economic problems, would be a close call for Reagan, but the latest Post-ABC poll has Reagan leading by 52 to 38 percent. Private surveys had it much closer but show the trend toward Reagan. Philadelphia Mayor Wilson Goode (D) is attempting to orchestrate a big black voter turnout, but there are signs of ticket-cutting in white wards.

Of the seven House races being watched earlier in the campaign, a few now seem very closely contested.

Rep. Bob Edgar (D), who always has a struggle in his Philadelphia suburban area, has a particularly strong opponent this year in Delaware County Councilman Curt Weldon (R), whom Reagan came to boost last week. But Edgar is a survivor. Rep. Peter H. Kostmayer (D), another suburbanite, lost his seat to Reagan coattails in 1980, but has a bit better chance to hold on against David A. Christian (R), a first-time candidate. Three challenged Republicans, Reps. Don Ritter, Tom Ridge and William F. Clinger Jr., are all slight favorites, and lawyer Paul E. Kanjorski (D) should pick up the coal-country seat of Rep. Frank Harrison (D), the man he beat in the primary. Rhode Island (4)

Historically one of the most Democratic states in the country, Rhode Island may be changing. The presidential race is rated a tossup, and the latest Post-ABC poll and other surveys show Cranston Mayor Edward DiPrete (R) clearly ahead of state Treasurer Anthony J. Solomon (D) in the race to succeed retiring Gov. J. Joseph Garrahy (D), the latest in an unbroken line of Democratic governors extending back to 1968. In the Senate race, however, four-term Sen. Claiborne Pell (D) is headed for a landslide reelection over business executive Barbara Leonard (R). Vermont (3)

Although Reagan has never been terribly popular with the independent electorate here, Democrats have made a minimal campaign effort and the president is running about 15 points ahead in public and private polls.

When four-term Gov. Richard A. Snelling (R) decided to step down, former lieutenant governor Madeleine M. Kunin (D), who ran a respectable race against Snelling in 1982, was the immediate favorite. Late polls, including the Post-ABC survey, have shown her running even with state Attorney General John J. Easton Jr. (R). The state constitution requires the winner to receive at least 50 percent of the total vote; with three minor candidates on the ballot, the contest could go to the state House of Representatives, where Republicans hold control and are expected to remain in the majority. West Virginia (6)

Another one of the "Carter Six" states and suffering from the highest unemployment in the country, West Virginia should be made to order for Mondale -- but is not. Reagan has impressive strength among blue-collar workers and fundamentalist whites and has been holding about a 7-point lead in the polls -- not a safe margin but a consistent one.

Two of the biggest names in West Virginia politics have run into some unexpectedly tough problems this year. Gov. John D. (Jay) Rockefeller IV (D), seeking the Senate seat of retiring veteran Sen. Jennings Randolph (D), has spent as lavishly as usual against his inexperienced opponent, wealthy businessman John R. Raese (R).

Raese has made every mistake a tyro can make, but still has been rapidly gaining ground on Rockefeller, who carries high negatives from worsening economic problems during his second term as governor. The polls indicate Rockefeller may have about 55 percent of the vote, but Democrats are nervous.

The GOP's top card, ex-governor Arch A. Moore Jr., was the strong, early favorite to defeat state House Speaker Clyde M. See Jr., and reclaim his old job. But See has made effective use of scandal charges left over from Moore's earlier term and Moore has ducked press questioning and calls for income-tax disclosure. Recent polls have shown Moore holding onto a lead of approximately 10 points.

Two young Democrats, who in 1982 won House seats their fathers had held before them, are being hard pressed this year. Rep. Harley O. Staggers Jr. (D) is up against ex-representative Cleve Benedict (R), and Rep. Alan B. Mollohan (D) may have an even tougher race against Wheeling funeral director and civic leader James Altmeyer (R). The GOP thinks it will pick up at least one of the seats.