This year's elections are most comparable to the congressional contests in 1980, Sen. John McCainJohn Sidney McCainZuckerberg: Maybe tech should face some regulations Schiff mocks Trump: Obama, Bush didn't need staff warning 'do not congratulate' Putin GOP senator tears into Trump for congratulating Putin MORE (R-Ariz.) suggested Thursday.

McCain, who is running for reelection this year, hearkened back to the 1980 contests in which House Republicans gained 35 seats and Senate Republicans picked up 12 seats.

"I think maybe it'll be comparable to 1980, when Ronald Reagan became president and we gained control of the Senate," McCain said on KGUN radio in Arizona.

That election cycle was a presidential election year — a key difference from this year's midterm cycle, when both parties don't have a major, national candidate on whose coattails they will ride. The 1980 cycle handed Republicans enough votes to take over control of the Senate for two years, but still left the GOP well short of the gains they needed to take control of the House, which had been heavily Democratic.

Most Republicans have expressed hope this fall's elections would most closely resemble the 1994 elections, the year of the so-called "Republican Revolution." Those elections saw Republicans, during the second year of a Democratic presidency, a situation resembling their current one, sweep through enough seats to win back the House and Senate. The GOP won 54 seats that year in the House and eight in the Senate.

McCain, the party's 2008 presidential nominee, said he thought this year would be a "landmark" election, spurred by voters' concerns over government spending, higher taxes and an inflated national debt. But he said his party would need to lay out several concrete platform planks on which they'll promise action if they want to win back majorities.

"Republicans have to make promises and keep them," he said.

To win those majorities, the GOP must win 39 seats in the House and 10 seats in the Senate.