Freshman U.S. Rep. Brian Mast, R-Palm City, has raised big bucks for his closely watched 2018 re-election bid while spending some serious money to do it.

Mast’s campaign has collected more than $1.5 million through Sept. 30 — far more than the other three incumbents in Palm Beach County’s U.S. House delegation. Mast’s campaign has spent $622,816, including more than $400,000 on direct-marketing solicitations to potential donors and more than $136,000 for fundraising consultants.

Mast’s campaign began October with $921,256 in cash on hand for his 2018 race, according to a quarterly Federal Election Commission report filed over the weekend.

Two Democrats have opened campaigns in Mast’s Palm Beach-Treasure Coast District 18.

Lauren Baer, a former Obama administration foreign policy adviser, raised $251,680 after launching an exploratory committee in August and a formal campaign in September.

Attorney Pam Keith raised $90,085 after formally launching her campaign in July and added $60,000 of her own money in the form of a loan.

When it works, direct mail can allow a candidate – particularly one with a stirring biography like decorated Army combat veteran Mast’s — to build a broad national base of donors. Those donors typically don’t stroke big checks, but they often give repeatedly over the course of a campaign. Between July 1 and Sept. 30, Mast collected $324,354 from individual donors, with two-thirds of that coming from people who gave $200 or less. He also raised $89,795 during the quarter from PACs.

Fundraising numbers from other members of the county’s congressional delegation:

• U.S. Rep. Lois Frankel, D-West Palm Beach, raised $107,212 during the quarter and, including leftover money from previous campaigns, had $981,976 in cash on hand on Sept. 30. Republican Kurt Jetta recently jumped into the race for Frankel’s seat and said he has put $250,000 of his own money into his campaign.

• U.S. Rep. Ted Deutch, D-Boca Raton, raised $108,967 in the quarter and has $290,394 on hand.

• U.S. Rep. Alcee Hastings, D-Delray Beach, collected $70,530 and has $252,063 in the bank.