Republicans are worried that a Democratic takeover of the Senate is increasingly likely, and many are hoping for high turnout of President Trump’s conservative base in key states as the party’s last, best chance to hold on to power.
Polling in several Senate races, as well as in the presidential campaign, has turned so grim for Republicans that lobbyists in Washington are “game planning” for Democratic control of both the Senate and the White House. Democrats already hold a majority in the House and are likely to gain seats there.
“Everybody’s concerned. The business community is concerned,” said a veteran Republican lobbyist in Washington. “The last time we had Democratic control of the White House and Congress, we got Obamacare.”
Three weeks before Election Day on Nov. 3, the nonpartisan Cook Political Report predicted that Democrats will gain two to seven Senate seats.
A gain of two seats would keep the Senate in Republican hands, 51 to 49. A pickup of three seats would flip control of the chamber, if Sen. Kamala D. Harris is elected vice president and gives Democrats the tiebreaking vote as president of the Senate.
Democrats picking up more than three Senate seats would amount to a blue tidal wave.
The most vulnerable Republican incumbent is Sen. Cory Gardner of Colorado, who is trailing his Democratic rival, former Gov. John Hickenlooper, by 9 percentage points in the latest public poll in a relatively moderate state.
“He’s dead man walking,” a Republican Party operative said of Mr. Gardner.
Many Republicans are similarly pessimistic about the prospects for Sen. Martha McSally of Arizona, who trails Democrat Mark Kelly, a retired astronaut and a gun control activist, by 8 points in the Real Clear Politics average of polls. However, the most recent survey in Arizona, by the Trafalgar Group, showed Mr. Kelly up only 2 points, within the margin of error.
Republicans faced difficult math defending their majority since the start of the election cycle. Of the 35 seats up for election this year, 23 are held by Republicans and 12 by Democrats.
Cook rates six incumbent Republicans’ races as toss-ups: Sens. David Perdue of Georgia, Joni Ernst of Iowa, Susan M. Collins of Maine, Steve Daines of Montana, Thom Tillis of North Carolina and Lindsey Graham of South Carolina.
Mr. Graham’s opponent, Democrat Jaime Harrison, has broken Senate fundraising records in a race that is tied. Mrs. Collins is facing the most serious challenge of her tenure from Democrat Sara Gideon, who has held a narrow but consistent lead in polls.
Even three-term Republican Sen. John Cornyn of Texas, whose winning margin in general elections has never dipped below 12 percentage points, was downgraded by Cook to a “leans Republican” race. The Republican is leading Democrat M.J. Hegar by 7.6 points in the RCP average of polls.
Mr. Cornyn said Wednesday that he is optimistic about his own reelection but is “very concerned” about the fate of Mr. Trump and the Senate overall.
“The president’s a couple of points ahead in a place like Texas, and we know it’s closer or he’s down in some other states around the country,” Mr. Cornyn said on “Fox & Friends.” “I want the president to win. But we need the Senate as a firewall, because if it turns over to the Democrats, [Sen.] Chuck Schumer said everything’s on the table — court packing, statehood for D.C. and Puerto Rico, and the Green New Deal, and you name it. So we need to keep that majority.”
The most vulnerable Democratic incumbents are Sen. Doug Jones of Alabama, who appears headed for a loss against Republican former Auburn football coach Tommy Tuberville, and Sen. Gary Peters of Michigan. Mr. Peters holds a narrow lead over Republican John James, a veteran and businessman who has never held political office.
Trump campaign officials say they are optimistic that Mr. Trump will do better than Democrat Joseph R. Biden at turning out his base. They said this week that the confirmation hearings for Supreme Court nominee Amy Coney Barrett could boost turnout in states such as Michigan if Democrats make an issue of Judge Barrett’s Catholic faith, something Democrats have studiously avoided during the televised hearings.
Republicans are hoping that strong core turnout will help incumbents such as Mrs. Ernst in Iowa and Mr. Tillis in North Carolina.
“Many Republicans feel that they are in the same uncertain place as we were four years ago,” said Republican strategist Ron Bonjean. “Many believe the race is much closer than it is and that increased voter turnout will make the difference.”
Although some Republican candidates have tried to distance themselves from Mr. Trump in recent days, Republican Party consultant Ford O’Connell said that strategy is “a fool’s errand.”
“Control of the Senate is almost directly tied to the presidential race,” Mr. O’Connell said. “If Trump wins the state, it’s very, very likely that the Republican [Senate candidate] is going to win that state as well. If Trump wins North Carolina, Tillis wins. I don’t see a way that McSally wins Arizona without Trump winning Arizona. It’s clear that Republicans are voting for Donald Trump first and foremost.”
Mr. Trump has been running ahead of the Republican Senate candidate in six of the seven most competitive races, RCP President Tom Bevan noted last week. The exception was Maine, where Mrs. Collins was polling at 42.3% and the president came in at 39%.
But a Quinnipiac University poll for traditionally red Georgia released Wednesday showed Mr. Trump trailing Mr. Biden by 7 points, 51% to 44%. Mr. Perdue, Republican Sen. Kelly Loeffler and her Republican rival, Rep. Doug Collins, were trailing Democratic Senate candidates Jon Osoff and Raphael Warnock, by 6, 8 and 12 points, respectively.
The polling has looked so bleak for Republicans that nearly all the trade associations in Washington began planning months ago for a Democratic takeover, the Republican Party lobbyist said. They are reviewing which Democrats would become Senate committee chairmen, for example, and girding their budgets for grassroots organizing against an expected Biden presidency that would promote corporate tax increases and a pro-union agenda.
“He was a huge thorn in our side because he was the voice of labor in the Senate,” the lobbyist said of Mr. Biden. “He was the lead on most of their issues. If I’m a line of business that is really concerned about labor policy, I’m concerned that Joe Biden is going to be president.”
Some Republican analysts are encouraged that Mr. Biden and other top Democrats have been pushing their voters to go to the polls in recent days instead of voting by mail. They say it’s a sign that Democrats’ campaign for expanded mail-in balloting during the COVID-19 pandemic isn’t “covering” the projected vote totals they need to win various races.
But Republicans are particularly concerned about the party’s erosion of support among seniors, who are turning against Mr. Trump in significant numbers in public polls compared with four years ago.
“It’s a mixed bag,” one Republican operative said of the Senate races. “There’s no question that I’m rubbing a rabbit’s foot right now.”