Two Arizona Democrats are building up solid defenses in advance of 2010. First District Rep. Ann Kirkpatrick and 8th District Rep. Gabrielle Giffords — both members of the Democratic Congressional Campaign Committee’s Frontline program to defend vulnerable incumbents — both expanded their cash reserves in the second quarter of 2009 as they work to fend off likely Republican challenges for their seats.

Giffords raised $370,000 in the second quarter, boosting her cash on hand from $895,000 to an impressive $1.2 million. Kirpatrick raised less — $261,000 — but it helped her nearly double her available campaign funds from $241,000 at the end of March to $423,000 as of June 30.

Thus far, only Giffords has declared Republican challengers, led by GOP recruit and Iraq War veteran Jesse Kelly.