Like a fledgling leaving the nest, John Warner a month ago quit the politically rewarding routine of traveling as Elizabeth Taylor's husband and began his solo fight for enough delegates votes to win the Republican nomination to the U.S. Senate in Virginia.

For more than a year, actress Taylor and spouse attracted crowds and money for Virginia Republican candidates, building up name identification and GOP gratitude for him.

However, at gatherings of potential delegates to the state convention June 2 and 3, Warner has been saying: "We are a great team, Elizabeth and I, and she has focused new attention on the role of the candidate's wife, but this is my responsibility. I have to get the delegates on my own."

After a month of campaigning, his two leading opponents - former Gov. Linwood Holton and former National GOP cochairman Richard D. Obenshain - have come to regard former Navy Secretary Warner as an aggressive hawk.

Jeff Wainscott, Alexandria Republican chairman and an Obenshain supporter ruefully appraised Warner's success in the first phase of the contest for delegates in that city last week and said, "The Warner people are playing hardball and they are spending a lot of money."

By "hardball," Wainscott meant a relectless effort to paint party regular Obenshain as a sure loser in a general election. "Warner has made some inroads with people you would expect to be with Dick," he said. "He is doing it with a campaign casting doubt on Dick's ability to win."

Warner's pitch in the endless series of meetings he is holding with prospective delegates is blunt but artful. Standing in Mr. and Mrs. Thomas M. Hook's living room in Fairfax County last Wednesday, he said of Obenshain:

"One of my distinguished opponents boasts of the role he has played in building the Republican Party in Virginia. I'm proud of what Dick Obenshain has done to build the party, but ladies and gentlemen, I'm telling you that when we are campaigning at the factory gates at the shipyard in Newport News next fall, the workers there won't be worried about the Republican Party. They will be worried about meat and potatoes on the table. They will want to know what our candidate can do to steer defense contracts to Virginia."

Warner followed with a recital of his experience in managing the Navy's defense spending and his actions as secretary in the early 1970s that favored Virginia's Hampton Roads naval complex. "No politics involved," he told his audience.

Hard shots at his Republican opponents and potential Democratic opponents come up in every Warner speech.

At another meeting of potential delegates in Fairfax last Wednesday, he erroneously said of a leading Democratic candidate, former Attorney General Andrew P. Miller: "He has never worn the uniform of the United States, his experience has been limited to that one job (attorney general)."

In fact, Miller was an artillery lieutenant stationed in Korea in the mid 1950s. Informed of his error the next day, Warner frowned and said. "I didn't know that. That's poor staff work on our part."

Warner's political rough stuff is packaged in a smooth delivery that in substance and style wavers from Ronald Reagan to Bert Parks.

A sampler:

On America's youth: "I've talked to a lot of young folks and I want to tell you there is a revival going on in our country. They're working and they're saluting the flag."

On welfare cheaters, especially those with government jobs: "I'd build the jailhouse on top of them if I could."

On the Hatch Act, which bans partisan political activity by federal employes: "To my dying breath, I will defend the Hatch Act."

On federal employes: ". . . they are dedicated, conscientious people. They are not responsible for this spiraling, uncontrolled growth. They are good conservative folk."

On President Carter: "This nation is suddenly beginning to examine the mistake that it thrust upon itself when it elected the president of the United States, and that's regrettable. Every one of us . . . is a patriot and we want to support our president . . . We're America first, but this man is failing us."

On voter aspirations in the coming election: "So what's going to happen, Mr. and Mrs. America, this coming November? Well, I'll make the following prediction. The people are going to go to the polls and look for the individuals with the experience to prevent these kind of disasters - government that taxes us out of existence and a giveway of the Panama Canal."

Warner served as director of the U.S. Bicentennial Commission after his five years in the Navy Department, and it has left him with a penchant for flag-waving rhetoric. A favorite technique is celebrating someone, preferably in the audience, as a personification of America.

Last summer, at a rally for successful Republican gubernatorial candidate John. N. Dalton in the coalfield town of Wise, Warner turned his speaking charms on James Brown, a young, self-made mining millionaire, and said: "Jim, you have taken a few bucks and turned them into a lot of bucks. Jim Brown, you are America."

Warner takes the edge off his conservative themes with an occasional stroke of what he calls "realism" born of his Washington experience. He told a very conservative audience in the Lee District of Fairfax, "I think we're always going to have some measure of a federal budget deficit."

It was not what they wanted to hear, but he stuck with it through their grumbles. After more than an hour of questioning, some of it from people trying to ellcit tougher stands, his reward came from a middle-aged woman who said, "Well, you sound good, Mr. Warner, your ideas and all."

By persistently questioning Obenshain's electability, Warner gives the impression that he feels the former party chairman is the candidate he has to beat. Obenshain has high standing with city and county chairmen throughout the state, persumably giving him an advantage in a convention.

Warner makes few allusions to Holton.Almost everyone involved in the Republican campaign says Warner is hitter at Holton for entering the race after leading him to believe he would not.

Holton is a partner in the Washington law firm of Hogan and Hartson, where Warner was a partner when he joined the Nixon administration. "When I introduced him at the firm," Warner said in an interview, "Linwood assured the partners he wasthrough with politics."