Royce's Orange County district is now considered vulnerable in the midterm elections.
The list includes including Financial Services Committee Chair Jeb Hensarling of Texas, Committee on Science, Space, and Technology Chair Lamar Smith, also of Texas, Judiciary Committee Chair Bob Goodlatte of Virginia, Transportation and Infrastructure Committee Chair Bill Shuster of Pennsylvania and House Administration Committee Chair Gregg Harper of Mississippi. Four years earlier, Republican Mitt Romney narrowly won the district.
Royce had appeared to be gearing up for another campaign: He had $3.4 million stockpiled in his campaign account as of September, the most recent numbers available.
Royce, 66, has served in the lower chamber since 1993. As Sean McElwee recently noted at The Outline, a majority of both college educated and non-college educated white people - voting blocks Democrats have been trying to court in recent months - support progressive economic policies, including a millionaires tax, more banking regulations, and increased health care spending. In 2016, Democrat Hillary Clinton carried the district by almost double-digits.
The 39th district consists of the most northern portion of Orange County from parts of Buena Park, Placentia and Anaheim Hills and contains all of Yorba Linda, Brea, La Habra and Fullerton while reaching north to portions of neighboring Los Angeles and San Bernardino counties.
"In the suburbs, Trump is toxic", Pitney said. There are seven Democrats in the House who also have announced that they will retire at the end of their terms. In order to take control the House, Democrats need to gain 24 seats in November.
Royce, who has represented his Orange County congressional district since 1993, is serving his past year as head of the influential committee under the term limits for chairmanships adopted by the House Republican caucus.
Another Republican seat in Congress will be up for grabs in this fall's midterm elections.
"We have just one message for Democrats who think they can compete for this seat: Bring it on", Stivers said.
"In a district that Hillary Clinton won by 8 points, Democrats are poised to win this Orange County seat and send someone to Washington who truly represents the values of Southern California", said Drew Godinich, a spokesman for the Democratic Congressional Campaign Committee. Five Democrats have already jumped into the race to replace Royce, and under California's primary system, known as the "jungle primary system", the top two vote-getters will go on to the general election, regardless of party.