As the final, frantic hours of the campaign for control of Congress come to a close, Democrats look like slightly-better-than-even favorites to reclaim the Senate, while Republicans appear certain to hold the House after a Donald Trump-induced October scare.

If Democrats manage to flip the Senate, senior party aides and strategists involved in battleground races said they’re looking at a majority of 52 seats, best case. That would be a letdown from their earlier hopes of a 54- or 55-seat advantage and put Republicans in the pole position to win back the chamber in 2018.


Senate Republicans are conceding nothing, though. The conservative Senate Leadership Fund has poured a jaw-dropping $37 million into the most competitive races over the past two weeks. Republican hopefuls are outperforming Trump and could conceivably prevail in enough of the half-dozen top contests to prevent a Democratic takeover.

“We are going to keep the majority,” declared Arkansas Sen. Tom Cotton, a vice chairman of the National Republican Senatorial Committee who has barnstormed the country this fall to campaign for GOP lawmakers. “I don’t think the presidential race will be a major factor … [voters] distinguish between the presidential race on the one hand … and the Senate races.”

Democrats’ confidence is rooted in Hillary Clinton’s narrow edge in national polls, which they believe offsets a late-game injection of uncertainty courtesy of FBI Director James Comey. Democrats need to pick up four seats if Clinton wins, and five if Trump prevails.

“I have a little heartburn over what Comey did. I think it was bizarre; I wouldn't have ever expected that in a million years,” Sen. Claire McCaskill (D-Mo.) said in an interview. But “I just don't see how [Trump] could ever pull this off. And I also feel pretty good about the Senate races.” (The interview occurred before Comey announced Sunday that he's standing by his conclusion that Clinton should not be prosecuted for her handling of classified material.)

On the House side, meanwhile, most political insiders agree it’s likely to remain safely in Republican hands as the threat of an anti-Trump wave has dissipated. House Republicans privately assert that a number of GOP incumbents once considered to be most at risk of losing — including John Katko and Lee Zeldin of New York, Carlos Curbelo of Florida and Mike Coffman of Colorado — are leading their Democratic challengers.

Hill Republicans are hoping to keep their losses to under a dozen seats.

“I feel like we’re in the best shape we could possibly be in, given that it’s a presidential election cycle,” Rep. Steve Stivers (R-Ohio), a deputy chairman of the National Republican Congressional Committee who’s expected to take over the organization next year, said in an interview. “I am certain Democrats will not take back the House; it’s not even a possibility.”

It’s surprising that the race for the Senate is as close as it is, given that Republicans are defending 24 seats, many in blue and purple states, and running with the bombastic Trump atop their ticket. Ironically, they have Trump to thank: As he recovered slightly in the polls the past two weeks, so did Republicans’ dwindling chances of keeping the Senate.

The New York Times’ Upshot model has Democrats’ chances of winning the chamber at 53 percent, while Nate Silver's FiveThirtyEight says it’s 50-50. Charlie Cook told NBC's Chuck Todd over the weekend he believes Democrats will pick up at least four seats.

GOP senators are pulling out all the stops to cut through the noise in the presidential race. Sen. Kelly Ayotte (R-N.H.) is aiming to make 50 campaign stops in five days, capped by a 24-hour sprint. Sen. Pat Toomey (R-Pa.) is spending the last days of the race sparring with President Barack Obama after running an ad showing the president praising Toomey’s work on gun control. And Sen. Ron Johnson (R-Wis.) spent the weekend with House Speaker Paul Ryan (R-Wis.) on a tour of a state where GOP skepticism of Trump runs deep.

As many as eight Senate races could go either way. Illinois is the lone safe pickup for Senate Democrats. But sources in both parties privately admit that Democrats are favored to take back the majority given the sheer number of GOP-held states in play.

Democrats believe that Johnson will fall short in his comeback bid, though they are fretting about former Sen. Evan Bayh (D-Ind.), whose lead in Indiana has evaporated. Republicans wish they had a few more days to prosecute their case against Bayh in what is being cast as a bellwether race.

“If a Democrat wins there, it’s probably a sign that they’re going to get a big number of seats,” Amy Walter of the Cook Political Report said Sunday on “Face the Nation.”

Some states are moving Democrats’ way at the last moment. A surge of Latino early voters in Nevada “probably” will lift Democrat Catherine Cortez Masto over Rep. Joe Heck (R-Nev.) in the only state where Republicans are on offense, Nevada political writer Jon Ralston concluded over the weekend. And 10 of the past 12 RealClearPolitics polls give Katie McGinty a lead over Republican incumbent Toomey in Pennsylvania, where Republicans say Toomey’s strong campaign may be swamped by Democrats’ million-voter registration advantage.

New Hampshire’s race, between Sen. Kelly Ayotte and Democratic Gov. Maggie Hassan, is viewed as the purest toss-up.

“In a small state with lots of polls in the field simultaneously and voters' phones ringing off the hook, it's difficult to get a representative sample,” said Aaron Jacobs, a spokesman for Hassan, after a rash of polls narrowly favored Ayotte.

Two conservative states are moving different ways, according to internal party assessments. Republicans have little confidence in Sen. Roy Blunt (R-Mo.) pulling it out against young and charismatic Democratic hopeful Jason Kander.

But Democrats seem less bullish about knocking off Sen. Richard Burr (R-N.C.) than they were two weeks ago.

Burr's hopes appear directly tied to Trump’s performance in his home state, a must-win for Republicans to take the presidency.

“There’s no question that Donald Trump has had an enormous amount of momentum. And it’s helping his chances and the senators out there that are running,” Republican National Committee Chairman Reince Priebus said Sunday on ABC’s “This Week.”

Though Florida is competitive, Republicans are confident that Sen. Marco Rubio’s universal name ID and big money advantage will prevail. But keeping the majority will essentially require Republicans to run the table elsewhere.

Control of the Senate will be critical for the next administration to confirm its nominees. And the slimmer the House majority next year, the tougher it will be for Ryan to govern the House Republican Conference.

The conference could lose up to three senior Republicans. Rep. Scott Garrett’s (R-N.J.) refusal to support gay Republican candidates is costing him in his New Jersey district outside New York City. And Republicans are nervous about longtime Reps. John Mica (R-Fla.) and Darrell Issa (R-Calif.).

Seung Min Kim contributed to this report.