Dallas — Elizabeth Dole, Strom Thurmond, and Trent Lott have some things in common that could be significant to the future of the Republican Party. They are all from the South.
They all began their political careers as Democrats.
They all switched and became Republicans.
Party leaders - who wrapped up their harmonious Republican convention here last night - get increasingly excited about their Southern prospects. People like Mrs. Dole, Senator Thurmond, and Representative Lott are one significant reason.
Party-switching isn't frequent - but it keeps adding weight on the Republican side.
Backing that up is growing Republican sentiment in the South. It has become so strong that White House strategists say the South today is almost a second base of support for Ronald Reagan, in addition to his native West. The South is a major reason that Walter Mondale is so far behind in the polls.
People have been excited over Republican prospects in the South before. There was the 1950s, for example, when thousands of Southerners drove around with bumper stickers on their cars that read ''Democrats for Ike.''
Then there was 1964. Republican Barry Goldwater, with his tough talk on foreign policy and tightfisted economics, seemed just the ticket in the South. But again, the hopes for a strengthened party faded after Election Day.
Over the years, however, the GOP has managed to chip away at Democratic solidity in Dixie. Republicans have rolled up a good record in presidential races. At lower levels, progress has been slower. There's only one Southern Republican governor today, for example - in Tennessee. But there have been a some breakthroughs for the party in other areas.
There was the celebrated case of US Rep. Phil Gramm of Texas. He was the maverick Democratic member of the Finance Committee who sided with President Reagan on the economy and leaked Democratic secrets to the Republicans.
The infuriated Democratic leadership threw him off the committee. He immediately quit the party, resigned his seat, went home, ran for the same seat as a Republican, and won. The GOP, of course, immediately put him right back on the Finance Committee - this time as a Republican.
Perhaps just as important in the long run, some local Democrats are also making the switch. This is giving the GOP better candidates with which to challenge the Democrats.
In South Carolina, for example, Lois Eargle, a local Democrat, was persuaded to jump parties and run as a Republican this fall. She will challenge incumbemt Democratic Rep. Robert Tallon in what looks like a hard-fought race.
In Alabama, former Democratic state legislator James T. Waggoner also became a Republican. He is running for a US House seat in the Birmingham area now held by freshman Democrat Ben Erdreich. Mr. Waggoner has already raised $170,000 for his campaign, a respectable amount for a House contest.
The most recent switch came when Andy Ireland, a Democratic congressman from central Florida's 10th District, registered as a Republican on July 5. Interestingly, in his conservative, pro-Reagan district, which includes Bradenton and Lakeland, the move scarcely made a ripple.
Mr. Ireland, joining in the applause for President Reagan here at the convention, said he felt delighted with his new party credentials. He explained that the benefits of remaining a Democrat just didn't seem very great. In fact, Ireland says that as a boll-weevil (conservative) Democrat, he had some of the same complaints that Jesse Jackson makes about the Democratic Party.
The liberal, Northern Democratic leadership uses black and Southern white votes to gain a majority in the House, Ireland says. Then the leadership denies Southerners and blacks many of the benefits of victory.
The reason, so far as boll weevils are concerned, is obvious. ''The national Democratic Party is not in tune with the majority of the people in the South,'' he says. Conservative Democrats are put at the end of the line.
Further, since the House did away with the old committee system, which gave long-tenured Southerners positions of great power, Southern influence in the House has been steadily eroded.
Even getting a good committee assignment can be tough for Southerners. Ireland cites the case of Dan Mica, a Florida Democratic congressman.
Mr. Mica was slightly senior to other Democrats when assignments were being passed out on the Foreign Affairs Committee of the House. He wanted the chairmanship of the Inter-American Affairs Subcommittee or the African subcommittee. He got neither. By votes of 10 to 11, the chairmanships went to other, less senior but more liberal members. Mica got another chairmanship - but that was two years later.
''Obviously he wasn't very happy about it,'' a Mica aide says.
Defending the Democrats, however, Mica's aide says that while Ireland may have a point, that point should not be carried too far. He observes that Florida Democratic members, for example, still are chairmen of three full House committees, including the most powerful, the Rules Committee.
Ireland observes that another great attraction of his new party was President Reagan. Says Ireland:
''It was with some chagrin ... that I noticed in 1980 that the country had elected a (Republican) President who thought as I did: that tax, tax, tax and spend, spend, spend was fundamentally wrong; that government had to balance its budget; that inflation could be brought under control; that interest rates could be brought down.''
Reagan, of course, once led the way for all these party-switchers such as Ireland, Lott, and Mr. Gramm. Reagan, too, was once a Democrat.