Last summer, Kate Steinle was walking with her father on a San Francisco pier when she was fatally shot by an illegal immigrant. Her murderer was a convicted felon and should have been behind bars.

San Francisco is one of more than 300 communities across the country that offers a safe-haven for illegal immigrants. These are known as sanctuary cities. The extreme policies of these communities ignore federal immigration law and protect illegal immigrants from deportation. This is why, despite having been convicted of seven felonies and deported five times, Kate's murderer was released from custody and walking the streets.

Despite a request three months earlier by the Department of Homeland Security for police to hold this violent criminal until federal authorities could pick him up, the city refused to cooperate and released him, in line with its sanctuary policy.

Sanctuary policies threaten the safety of our citizens and undermine the enforcement of our immigration laws. Allowing communities to purposefully protect violent and dangerous criminals who are in the country illegally is wrong.

Unfortunately, Kate's murder is not an isolated incident. Thousands of criminals remain in this country, protected by these sanctuary jurisdictions. Public safety needs to be a priority. Cooperation between local and federal law enforcement plays an important role, but the Obama Administration isn't doing enough to hold these communities accountable.

It's no surprise considering the President's pattern of rewarding illegal immigrants. The President's directives to stop enforcing certain immigration laws are a threat to public safety. Fortunately, the recent ruling by the Supreme Court affirms that President Obama's executive actions to allow amnesty for people in the country illegally is a gross overreach of power. This abuse of authority by the President was rightfully reined in with this decision that prevents him from choosing not to enforce our immigration laws. Cities across the country have the same responsibility.

We need to improve our laws to deter illegal immigrants who have been deported from reentering our country illegally and end sanctuary cities. That's why I'm leading the fight to hold sanctuary cities responsible for their dangerous practices.

In early July I voted in support of the Stop Dangerous Sanctuary Cities Act. This legislation would restrict federal funding from sanctuary communities that fail to comply with the law in an effort to encourage them to eliminate the dangerous policies and allow local law enforcement to cooperate with federal immigration officials. It's only fair that they aren't eligible for certain federal funds if they don't follow the law.

Public safety needs to be a priority for the communities that maintain a sanctuary city policy. That's why I was proud to support Kate's Law, to prevent other families from suffering the same heartache as the Steinle family. This legislation establishes a mandatory minimum sentence of five years for illegal immigrants who are found guilty of reentering the U.S. after being convicted of an aggravated felony or being convicted of having illegally reentered the U.S. twice before.

Protecting the security of the American public shouldn't fall along party lines, but Democrats blocked the Senate from continuing to debate either of these bills. We owe it to Kate to prevent more senseless tragedies enabled by sanctuary city policies. I will continue to fight to hold sanctuary cities accountable and strengthen border security.