HARRISBURG - Proposals to trim the size of the Pennsylvania General Assembly have been floated, and swiftly shot down, for decades.

But now there may be some muscle behind that nearly half-century-old idea.

Supporters, including Gov. Corbett, House and Senate leaders, and reform-minded backbenchers, say the time is ripe to shrink what, with 253 members, is the largest full-time legislature in the nation.

Proponents say a smaller legislature would reduce costs and make government more effective. Opponents have argued that the current constituent-to-lawmaker ratio provides better government access.

House Speaker Sam Smith (R., Jefferson), once an opponent of legislative downsizing, told the House State Government committee Tuesday that his bill - cosponsored by House Majority leader Mike Turzai (R., Allegheny) - would improve members' understanding of legislation and the ability to reach consensus.

Smith wants to drop the number of House members from 203 to 153 while keeping the Senate membership at 50. He said he chose 153 because some mathematical studies suggested it was a manageable number.

As it is, he said, the chamber's size has made debates messy affairs.

"I've watched people stand and sit down out of frustration," Smith said.

Each House member represents about 63,000 people; Senate members represent 254,000. Under Smith's proposal, the number represented by each House member would rise by about 20 percent.

Smith's bill is one of five introduced in the House this session to reduce the size of the legislature. At least one - cosponsored by Senate Majority Leader Dominic Pileggi - has been introduced in the Senate.

Corbett, who campaigned on a government reform agenda, supports the downsizing effort.

If "we get that on the ballot, I'd be very surprised if it didn't pass," Corbett told the Pittsburgh Tribune-Review during an event in Pittsburgh on Monday.

Still the committee chairman, Rep. Daryl Metcalfe (R., Butler), was noncommittal about bringing any of the bills up for a vote this fall, saying he planned to discuss them first with House leaders.

The hearing Tuesday revealed two unusual bedfellows among downsizing opponents: Philadelphia lawmakers and Pennsylvania farmers.

Rep. Mark Cohen (D., Phila.) called a smaller General Assembly a "terrible idea." He challenged the notion that it would reduce the cost of the legislature and said that it would make it more expensive to win a House seat because a candidate would have to campaign in a larger district. Also, larger districts would limit constituent access to lawmakers, he said.

He said that the legislature's $300 million budget represents 1 percent of the state budget and that eliminating 50 seats would have the same impact as closing one high school.

John Bell, the government affairs counsel for the Pennsylvania Farm Bureau, which represents 53,000 farmers, said his group feared larger districts would mean less representation for the agricultural community and its interests.

Beverly Cigler, a professor of public policy at Pennsylvania State University, told the committee that slicing the legislative staff would be "more productive" than reducing the legislature.

"Staff costs drive the budget," she said, adding that many positions are duplicative because the Democrats and Republicans hire different staffs to do essentially the same jobs, such as research.

There are nearly 3,000 people employed by the House and Senate in Harrisburg and 400 district offices across the state.

Regardless of the current wave of enthusiasm, even if approved, the legislature would not shrink overnight.

A bill to reduce the size of the legislature would have to be approved by the General Assembly in two consecutive sessions - that means as many as four years - and then be put before the voters in a referendum.

And several of the bills - such as Smith's - would not begin downsizing until after the next census and legislative redistricting, in 2020.

Contact staff writer Amy Worden at 717-783-2584 or aworden@phillynews.com.