(NewsNation) — The presidential race may be tough, but the fight for control of Congress may be tougher for Democrats. The latest forecast from The Hill/DDHQ says that Republicans have a 70% of taking control of the Senate and a 56% chance of retaining control of the House.

“Democrats have their backs against the wall. They don’t have much room to lose,” said Washington lobbyist and consultant Christopher Neiweem.

“I think they’re going to get it by two seats, even a third,” he told NewsNation. “This is strong math favoring Republicans. Senate Democrats are going to have a challenge here.”

Neiweem said the Senate seat that’s dead certain to switch is West Virginia, where Democrat-turned-Independent Joe Manchin is retiring.

“West Virginia is a total takeaway for the governor there stepping in to replace Senator Manchin,” he said. Republican Gov. Jim Justice has a formidable lead in every poll, and The Hill/DDHQ predicts he has a 99% chance of winning.

The other seat most likely to switch from Democrat to Republican is Montana. Despite his longtime popularity, Democrat incumbent Jon Tester is trailing Republican Tim Sheehy, a retired Navy Seal turned aerospace CEO. The Hill/DDHQ predicts that Sheehy has a 73% chance of winning.

Neiweem says there are several factors still at play, including voter turnout – which will be greatly influenced by the presidential race.

He also says three races that had been considered toss-ups – Nevada, Ohio and Arizona – are now tilting toward the Democrats. But he predicts that the Republican incumbents in Texas and Florida, Ted Cruz and Rick Scott, will win their races.