First-term Senators could make up 40 percent of the chamber next year, wielding significant influence over their parties and the institution itself.
The seniority shift comes after two consecutive cycles of Democratic gains, and a 2010 election that is likely to give Republicans a historic number of new Members.
“The clash is going to come when the new crop of Republicans meets the newer classes of Democrats who have absolutely had it with the Republican stalling tactics of the past couple of years,” said one senior Senate Democratic aide who has worked in the chamber for decades.
Many of the Republicans who win this year will have conservative tea party enthusiasts to thank, and they will come to the Senate prepared to stand firm against President Barack Obama’s agenda.
By contrast, the 2006 and 2008 classes of Democrats are largely liberal-leaning and have been using their first terms to try to change Senate rules so Republican lawmakers, such as Sens. Tom Coburn (Okla.) and Jim DeMint (S.C.), cannot block Democratic priorities.
Republican Conference Chairman Lamar Alexander (Tenn.) said he hopes the group of incoming GOP Senators will “diminish the enthusiasm among some of the new Democrats to rip the Senate apart by destroying minority rights” in their push to limit or eliminate filibusters.
But the longtime Senate Democratic aide warned that if Democrats hang onto control of the chamber, junior Members may have even greater incentive to change the rules, especially if “the newer crop of Republicans brings the place to a [legislative] standstill.”
Republicans are expected to win at least 11 seats, and polls favor the GOP in 10 more races this year, according to Roll Call’s current ratings. Eight other races have been rated tossups.
The potential for 21 or more new Republican Senators would rival the 20 Democrats who joined the chamber over the past two election cycles.
Alexander said, “It’ll be a historic number of new Republicans.”
“It’s going to form the core of the Republican Senate for the next two decades and form the next generation of leaders,” he said.
The makeover could be so dramatic that Sen. Scott Brown (R-Mass.) could jump from being ranked dead last, or 41st, in party seniority to 33rd, after serving less than a year, Alexander said.
And Alexander argued that the class may not tilt as heavily to the right as many have suggested. Instead, he said Republican freshmen are likely to have “diverse points of view.”
Still, he predicted Republicans would have near unanimity “on the debt, limited government and free markets.”
“On our side, we need to make sure we listen to what the voters are saying this year,” Alexander said.
But one veteran Democratic Senator said Alexander and other GOP leaders could be surprised by the desire of new Members to upset the way the chamber operates.
“Most people over the decades have come to the Senate ... and taken their time to integrate into the institution,” the Democratic Senator said. He added that has not been the case for the Democratic classes of 2006 and 2008.
Former Sen. Scott Brown, R-Mass., candidate for U.S. Senate in New Hampshire, holds his hand over his heart during the singing of the national anthem as he waits to take the stage for his town hall campaign rally with Sen. John McCain at the Pinkerton Academy in Derry, N.H., on Monday, Aug. 18, 2014.