In the crucial battle for early voters in Iowa that could foreshadow which party has the edge in the midterm elections, Republicans led Democrats for the first time Wednesday, GOP officials announced.

The Republicans closed the day with an advantage of 305 of combined early votes and absentee ballot returns, giving them an advantage they have never held in any Iowa campaign. An overhauled ground game that prioritizes early voting is a key part of the Republican strategy to boost state Sen. Joni Ernst over Democratic Rep. Bruce Braley in their close race for an open Senate seat.

Republicans also believe they are winning the battle to expand the electorate, something the Democrats have focused on to diminish the GOP’s historic turnout advantage in midterm elections. On Monday, among the best days for absentee-ballot requests for the Democrats, only 13 percent came from voters who did not participate in the 2010 elections; compared to 28 percent of GOP absentee requests who didn’t vote four years ago.

"The momentum has been building for a long time, but this development means Republicans have crossed a major Democrat firewall that had given them a boost going into Election Day in previous election cycles. Democrats are nowhere near where they need to be, and they are quickly running out of time.” Iowa GOP Chairman Jeff Kaufmann said in a statement.

“It’s been a great team effort in Iowa that has us in a great spot to win in November. We’ve completely revamped our ground game putting an emphasis on turning out low propensity voters before election day and its working," Republican National Committee Chairman Reince Priebus added.

If the Republicans maintain this level of performance with early voters, particularly those considered less likely to vote this year, it could signal that the GOP is headed for victory in a host of competitive races across the country. Winning a tough Iowa Senate race would also be another blow to the Democrats’ hopes of maintaining Senate control in the next Congress. Democrats have long been considered the early vote experts, as born out by their past success — particularly in Iowa.

Iowa Democrats noted that they have a lead over the Republicans of 18,000 in total absentee ballot requests. They expect those ballots to flood in between now and Nov. 4 and help them keep pace with what is usually higher GOP performance among Election Day voters.

"While the overall number of ballots submitted will fluctuate in the final days, Democrats have a significant advantage on the ground and are winning the early vote. Democrats are expanding the midterm electorate and are turning out non-midterm voters, while Republicans are simply encouraging their base to vote early," Iowa Democratic Party spokeswoman Christina Freundlich said.

Republican officials released additional figures from early and absentee voting in Iowa. The following was taken from a memorandum prepared for Republicans in Iowa and Washington by Cardinal Insights partner Mark Stephenson:

1) In an unprecedented ground game mobilization, Republicans surpassed Democrats in AB/EV Returns for the first time in modern Iowa AB/EV history on October 22, 2014.

* Today, cumulative Iowa registered Republican returns/early votes surpassed Democrats, to take a lead of 305 returned ballots. This is the first time registered Republicans have surpassed Democrats in returns.

* In 2010, the lead for Democrat returns at this point in the cycle was 16,426 ballots. In 2012, that gap was 56,908.

* For 2014, Republican absentee returns are up by nearly 50% over 2010, compared to only 18% for Democrats.

2) Republicans lead with in-person Early Voting, a place where Democrats historically have relied on large advantages going into Election Day.

* Republicans lead in-person absentee and satellite voting 24,818 to 24,483.

* Since in-person Early Voting began on 9/25, 19 total days, Republicans have led in 14 of those days.

3) The outstanding absentee ballot request gap is closer in 2014 than ever before at this point in the cycle.

* Currently, the total overall AB request gap between Democrats and Republicans is 19,605. At this point in the cycle, this is much closer than either 2010 or 2012.

* In 2010, the request gap at this point was 24,620. In 2012, the gap was 75,287.

* Republican requests are up 41.5%, compared to Democrat requests improving only 30.0% over 2010.

4) Republicans have steadily grown their vote share with a group of new, low propensity, non-midterm voting individuals each week, over the past six weeks. Their total share of these voters is growing every day, while Democrats’ share is steadily decreasing.

* Since October 1, when Republican contact efforts intensified, Republicans lead in total absentee requests from non-2010 voters by 7,678 voters.

* The share of non-2010 voters has grown steadily over the past weeks for Republicans, while decreasing for Democrats.

* In fact, on the Democrats’ biggest request day of the cycle, October 20th, nearly 28% of Republican absentee requests came from non-2010 voters, compared to only 13% for Democrats.

5) Democrats are now resorting to cannibalizing their 2010 voters, to keep up in the request race, keep their activists energized and hold onto their press narrative.

* Democrats’ largest request day of the cycle, October 20th, was made up by over 87% of 2010 voters, compared to only 72% for Republican on the same day.

* With each week, a higher percentage of Democrat 2010 voters requested ballots for 2014, starting with 75.0% for the week of September 29th, to 84.1% for the week of October 20th.

* Even more troubling for Democrats, their recent investment, in response to our sustained growth, was to mobilize 2010 absentee and poll voters – the very cannibalization they claimed they were not engaging in.

6) The Democrats’ lead is simply not sustainable or large enough to overcome Republican efforts going into Election Day.

* Historically, Republicans outperform Democrats, both in turnout and vote share on Election Day.

* Democrats went into the 2010 election with a request lead of almost 30,000 votes and a return lead of nearly 20,000 votes, but lost the Governor’s race overall by 108,000 votes.

* In addition, President Obama went into the 2012 Election Day with an AB/EV lead of 137,355 votes, but lost on Election Day by 45,428 votes.