Democrats could wrestle control of the U. S. Senate in next month's election.
Illinois Senator Dick Durbin, the second in command among Democratic senators, said during Sound Ideas only a swing of four votes would do the trick, although he said five would provide some padding.
Durbin said the populist nature of this campaign makes it difficult to predict how the race for the White House will impact other races.
"I know the realism of these campaigns and as important as the presidential choice is, as much influence as it has on voters, we still don't know what the net result will be," he said.
Durbin drew an analogy between the current campaign, which has seen Republican party leaders withdraw any support they had for nominee Donald Trump, and the 1964 presidential race, where extreme conservative Barry Goldwater lost to incumbent Democrat Lyndon Johnson in a landslide.
"In '64, Republicans stayed home. And when they stayed home, Democrats won down-ballot. I don't know what's going to happen here as more and more Republicans are estranged from the Trump candidacy," Durbin added.
Durbin said he spoke with minority leader in the House Nancy Pelosi this week. He said Pelosi told him winning the House was 'doable.'

Durbin went on to discuss how important it is to pass an appropriations bill this fall. He also talked about pressure Congress is applying to pharmaceutical companies over rapidly-increasing prices, and Wells Fargo's apparent violation of the federal Service-members Civil Relief Act. And he reiterated he has no plans to seek the office of Illinois governor.