How is it that the U.S. has been without an ambassador to Mexico since July while President Barrack Obama’s nominee for the post has languished in political limbo awaiting a confirmation hearing?

It couldn’t be the nominee’s credentials. Roberta S. Jacobson’s resume is impeccable. A career public servant who worked her way through the ranks of the State Department to become a senior diplomat, Jacobson is considered an expert on U.S.-Mexico relations.

Rather, it appears that the Senate has yet to confirm Jacobson because a few of its members are placing their personal agendas before the good of the nation. Republican presidential hopeful Sen. Marco RubioMarco Antonio RubioOvernight Cybersecurity: Bipartisan bill aims to deter election interference | Russian hackers target Senate | House Intel panel subpoenas Bannon | DHS giving 'active defense' cyber tools to private sector Senators unveil bipartisan push to deter future election interference Puerto Rico's children need recovery funds MORE of Florida and Democrat Bob MenendezRobert (Bob) MenendezCongress must provide flexible funding for owners of repeatedly flooded properties Senate ethics panel resumes Menendez probe after judge declares mistrial Judge declares mistrial in Menendez bribery case MORE of New Jersey, both Cuban-American, have reportedly put Jacobson’s nomination on ice because of lingering Cold War era resentments toward Cuba.

As assistant secretary of State for Western Hemisphere Affairs, Jacobson played a key role in defrosting diplomatic relations with Cuba, halting a failed and costly decades-long embargo and policy of interdiction.

Jacobson is uniquely qualified for the position as she has demonstrated unwavering leadership in advancing U.S. interests in the Western Hemisphere. Having served nearly 30 years with the Department of State, she has been involved in several strategic initiatives. Her work on the Merida Initiative, resolution of the U.S. “water debt” with Mexico, and commitment to the “100,000 Strong in the Americas” education exchange program are merely a few examples of how she is immeasurably qualified to assume this key diplomatic post.

Such a wrong-headed approach to this worthy, skilled diplomat not only echoes a failed cold-war mentality but does a great disservice to Mexico, California’s largest trading partner and the nation’s third largest behind China and Canada.

Earlier this year, I led a delegation of state senators to Mexico that highlighted the need to maintain and further stimulate relations with our southern neighbor to promote commerce, innovation, and trade. Due to our state’s shared border, critical issues including economic growth, cartel drug trafficking and illicit firearms trafficking, and immigration were at the forefront of our discussions.

Our meetings with key governmental and private sector leaders, including then-U.S. Ambassador Anthony Wayne, the secretary of Foreign Affairs, the president of the Mexican Senate, two Mexican governors, and entrepreneurial business associations were illustrative of the valuable relationship California shares with Mexico. Furthermore, the meetings demonstrated the importance of open dialogue in order to effectively coordinate our mutual interests. For these reasons, it is of paramount concern that the United States does not have official representation in Mexico.

With more than 34 million Americans of Mexican descent, 12 million of whom reside in California and include millions of Mexican-born naturalized citizens who have committed to this country—it is simply unacceptable for the United States to continue neglecting its relations with Mexico. The economies and peoples of California and Mexico are intricately linked, and it is imperative that we have U.S. representation to promote our strategic economic and security interests.

It is long overdue the Senate places the vital U.S.-Mexico relationship above personal agendas and Cold War modes of thinking and confirms the nomination of Jacobson.

De León is leader of the California State Senate.