Rep. Darrell Issa (R-Calif.) won't run for Sen. Barbara BoxerBarbara BoxerThe Trail 2016: One large crack in the glass ceiling Dem suggests race factored into Obama Senate endorsement Obama, Biden back Kamala Harris in Calif. Senate race MORE's (D-Calif.) seat, two sources close to the congressman tell The Hill.
Boxer announced that she will retire Thursday morning, triggering what's expected to be an expensive and crowded race to succeed her. Democrats have a clear advantage in the state, though some Republicans are holding out hope that they can compete in the race.
Issa has previously shown statewide ambitions — he lost a GOP primary to challenge Boxer in 1998 after spending $10 million of his own money and made some early moves toward a gubernatorial run in 2003.
Republicans in Washington, D.C., and California were already mentioning him as a potential candidate for the race before Boxer made her plans official, pointing to his ability to self-fund. Some also speculated that he might be interested now that he's no longer chairman of the House Oversight Committee.
His political team has also maintained a number of Web domains that could be used for a Senate run — IssaforSenate.org is registered to his chief political adviser, John Franklin, who re-registered the domain in 2014 after first claiming it in 2004.
But sources close to Issa point out that he's shown no inclination toward another statewide run for more than a decade, and note that California has become more Democratic during that period, making it harder for any Republican to win. Issa has also cut a more combative, partisan figure in the last few years as one of the GOP's main attack dogs against the Obama administration, an image that would likely not play well statewide.
One Issa adviser said not to "read much into" the domain registration.
"Every politician worth their salt owns every domain related to their name," said another.