WASHINGTON — Former Rep. Beto O'Roruke has been raising money at a faster rate than the rest of the 2020 Democratic primary field, his campaign said Wednesday, but Sen. Bernie Sanders has so far collected more money overall.

O'Rourke reported raising $9.4 million in the first quarter of the year at an average contribution of $43 a pop — well short of Sanders' $18 million and the $12 million Sen. Kamala Harris, D-Calif., said she raised.

But O'Rourke's campaign noted that the Texan entered the race much later than the others, giving him only 18 days to fundraise before the March 31 deadline, compared with the 41 days Sanders had between his February launch and the end of the quarter or Harris' 70 days following her January announcement.

O'Rourke raised about $522,000 per day, a faster clip than Sanders' roughly $440,00 dollar-per-day rate or Harris' approximately $170,000 per day.

"In just 18 days, people in every state and from every walk of life have organized in homes, contributed a few bucks online and united together," O'Rourke said in a statement. "Not only is this a sign of our grassroots strength during the first two weeks of our campaign but it is a sign of what's possible when you put your full trust in the people of this country."

Many of the Democratic candidates have not yet released their first-quarter hauls — reports are not due to the Federal Election Commission until April 15. But when the dust settles, Sanders, who raised over $200 million during his 2016 presidential run, is expected to lead the crowded field now that O’Rourke finished behind him.

O'Rourke raised more money than any Senate candidate in history during his unsuccessful run against Sen. Ted Cruz, R-Texas, last year, leaving him with a massive email fundraising list helmed by veterans of Sanders' 2016 online money operation.

Earlier this week, Mayor Pete Buttigieg of South Bend, Indiana, said he brought in $7 million.

Early fundraising is seen as a key measure of candidate strength, especially in the era of grassroots small-dollar donations, so campaigns compete aggressively to post the best possible results.

With O'Rourke and Sanders' numbers released, Democratic insiders are now most eager to see the results by the other best-known candidates, such as Sen. Cory Booker, D-N.J., and Sen. Elizabeth Warren, D-Mass., a one-time online fundraising juggernaut whose campaign has downplayed expectations in the wake of the controversy involving her Native American heritage.