Since tens of thousands of Democrats crossed party lines in Georgia’s primary, some Republicans are proposing a state law to restrict future primaries to voters who register as party members.

The idea to end Georgia’s open primaries, where any voter can choose either party’s ballot, follows complaints from former President Donald Trump and his supporters that Democrats tainted Republican races rather than voting for their own party’s candidates.

Recently updated turnout data that includes election day shows about 67,000 voters in this year’s Republican primary participated in the Democratic primary in June 2020. Those voters amounted to about 6% of all voters who cast ballots in the GOP primary. In comparison, 1% of this year’s Democratic primary voters participated in the Republican primary two years ago.

But it’s unclear whether there were enough crossover voters to make a difference in the outcome of races because many of them don’t have a well-established partisan voting record. About one-third of this year’s primary voters didn’t turn out for the primary two years ago, according to an analysis of state election records by The Atlanta Journal-Constitution.

Republican Secretary of State Brad Raffensperger avoided a runoff by about 55,000 votes in his victory over U.S. Rep. Jody Hice, who was endorsed by Trump.

Other contests weren’t as close, such as the lopsided race for governor in which Gov. Brian Kemp received 74% of the vote against four challengers including former U.S. Sen. David Perdue.

During a press conference Monday, incoming state Sen. Colton Moore, a Republican from Trenton in northwest Georgia, said political parties should be able to limit primaries to voters who share their principles.

“We’re trying to make the primary pure,” Moore said. “Even if it’s just a small percentage (of crossover voters), let’s say 2% or 3%, in a race, that’s enough to sway the outcome to where a party isn’t getting its nominee. Instead, it’s getting a nominee that was chosen by another party.”

To close Georgia’s primaries, a bill would have to gain traction in next year’s legislative session. Moore was joined by Vernon Jones, who organized the press conference and is competing in a Republican runoff for Congress against Mike Collins, and state Rep. David Clark, a Republican from Buford and critic of House Speaker David Ralston.

“There’s no need to change the current primary system,” said Kaleb McMichen, a spokesman for Ralston.

All of the Republican candidates in runoffs for Congress said during debates Monday that they endorse ending Georgia’s open primaries.

House Democratic Minority Whip David Wilkerson said he’s not surprised by calls to restrict primaries to party members.

“What we’ve seen over the last few years with Republicans is every time they don’t get a result they want, they want to change the rules,” said Wilkerson, who represents Powder Springs. “Does crossover voting impact elections a little bit? Maybe, but at the end of the day, I think the open primary has served Georgia well.”

Some Democrats say they voted strategically for Republicans to oppose candidates allied with Trump or to support candidates they see as more vulnerable in the November general election. Other voters participate in whichever party’s primary has more competitive races.

In 2020, some voters probably opted to vote in the Democratic presidential primary because it still offered a choice of candidates while the Republican race that year had only one competitor, then-President Donald Trump.

Georgia is one of 15 states with open primaries, which allows voters to choose either party’s ballot without registering with a political party, according to the National Conference of State Legislatures.

Primary systems in other states follow different rules, including nine states such as Florida with closed primaries that deter crossover voting by requiring voters to first register as a party member. Several states allow voters to participate in either party’s primary, but their choice can be considered a form of registration with a political party.

Last month’s Georgia election had a record turnout for a midterm primary, bringing in many new voters who didn’t show up two years ago, according to state election data. Their inconsistent voting record makes it difficult to assess whether they were crossover voters.

About 37% of Republican and 25% of Democratic voters this year didn’t participate in the June 2020 primary at all, according to state election data. That amounts to 642,000 new primary voters out of a total turnout of more than 1.9 million.

Crossover voting in May primary

67,000: That’s roughly how many Georgians voted in this year’s Republican primary who also participated in the Democratic presidential primary in 2020. Whether they were enough to sway a race is uncertain, though, because many voters don’t have well-established partisan voting records.

1 in 3: That’s about the share of voters who cast ballots in this year’s primary after skipping the primary two years ago.

32%: The percentage of voters in the Republican primary who didn’t participate in 2020 primary.

25%: The percentage of voters in the Democratic primary who didn’t participate in the 2020 primary.