Jordain Carney and Rafael Bernal, The Hill, July 3, 2017

The fight over immigration enforcement is moving to the Senate, where Democratic opposition will be tested.

The House passed a pair of immigration bills late last week: “Kate’s Law” to increase maximum penalties for criminal aliens who attempt to re-enter the country, and a second bill cutting funding to cities that refuse to comply with federal immigration laws.

Republicans got an unexpected boost when two-dozen House Democrats voted for “Kate’s Law,” viewed by GOP supporters as a first step toward implementing President Trump’s campaign promises on immigration.

The defections came after House Democratic leaders said they wouldn’t twist arms to get their members to oppose the legislation. But the outcome is raising questions about whether Democratic senators up for reelection in 2018 will similarly break rank as the fight shifts to the upper chamber.

Senate Democrats are expressing confidence that they’ll be able to block the bills if they are brought up for a vote.

“I will do whatever I can in order to stop them. These are only punitive in nature, they don’t deal with the totality of the reality of our immigration challenge, and as a continuing part of the Republican saga that only looks at one element, and looks at it in a way that is totally disproportionate,” Sen. Bob Menendez (D-N.J.) said.

Democrats previously blocked similar proposals in 2015 and 2016. But a renewed push could force the 10 senators running for reelection in purple and red states won by Trump to take a tough, politically controversial vote.

A top House Democratic aide predicted that “Kate’s Law” would be used in campaign ads against vulnerable Democrats.

“The ad writes itself,” said the aide. “They’re gonna use Kate Steinle’s picture in a Willie Horton-style ad,” referring to a controversial 1988 TV ad used by President George H.W. Bush’s campaign against Michael Dukakis.

Red-state Democrats are remaining tightlipped about the two immigration bills amid the fight in the Senate over repealing ObamaCare.

But Democratic Sens. Joe Donnelly (Ind.), Joe Manchin (W.Va.) and Heidi Heitkamp (N.D.) previously voted to take up a bill toughening penalties on some undocumented immigrants who illegally re-enter the country after being deported.

{snip}

Republicans will need to win over at least eight Democratic senators to pass any immigration or border security bill. Spokespeople for Manchin and Donnelly didn’t respond to a request for comment about their positions.

If the three Democratic senators did vote with Republicans on a proposal to impose tougher penalties on undocumented immigrants re-entering the country illegally, GOP leadership would still need to flip an additional five senators.

Their targets would likely include Democratic Sens. Claire McCaskill (Mo.), Bob Casey (Pa.), Sherrod Brown (Ohio), Bill Nelson (Fla.) and Jon Tester (Mont.) — each up for reelection next year in states won by Trump.

There are already early signs that a vote for or against the bill would be prime fodder for the 2018 election, where Democrats are defending 25 seats and Republicans are only protecting eight.

{snip}