Trump’s immigration policies have been a failure. Neither he nor Democrats have much of a solution to the current problem.

For the president, immigration is a proxy for many issues — national security, domestic security, cultural change, nationalism, even nostalgia. The president’s rhetoric inflames the left as much as it energizes his loyalists, which is exactly his purpose. Democrats oppose Trump’s policies and cry foul when he seeks to blame them. They also point out that Trump tried to use immigration during the closing weeks of last year’s midterm elections, only to see his party lose its majority in the House.

Immigration will continue to animate Trump’s core supporters and will likely be one of two pillars of his reelection campaign. The other is the economy, the issue he will look to as a bridge to other voters whose support he will need to win what looks to be an extremely competitive election. Here, too, the Democrats appear to be struggling to find their own voice on what should be a central part of a presidential campaign message.

.. The new Battleground Poll by the Tarrance Group and Lake Research Partners under the auspice of Georgetown University’s Institute of Politics and Public Service shows the president holding a clear advantage over Democrats in Congress on which party people trust to deal with the jobs and with the economy. Democrats need to narrow or reverse that margin.

As an insurance policy, Trump has already gone on the attack against the Democrats on the economy, playing the “socialism” card. He has seized on Democratic proposals for a Medicare-for-all health-care plan and a Green New Deal, both of which in their most expansive iterations would require a heavy dose of government intervention and regulation, warning of dire consequences to the economy.

Candidates like Sen. Bernie Sanders (I-Vt.) and Sen. Elizabeth Warren (D-Mass.) have economic messages built around populist us vs. them themes, including attacks on big corporations and wealthy individuals. Their platforms contain the broad promise to rebalance the economic scales in favor of middle- and working-class Americans, in part through a variety of new taxes on those corporations and wealthy individuals. Warren in particular has offered a fresh list of detailed policies.

Most of the Democratic presidential candidates favor new taxes on the wealthy. But at this stage, most haven’t really said how they would pay for what they propose. The Democrats are often more focused on other issues than on the centrality of the economy in the lives of voters. Another sign of a lack of consensus in the party is the inability of House Democrats to agree on the outlines of a new budget.

The president has begun to set the themes for his reelection campaign. Democrats have vowed not to make the mistakes in 2016 of focusing too much on Trump’s fitness to be president. But they can’t ignore legitimate questions about how they would govern — or how they will credibly respond to the president’s attacks on his issues of choice.