Trump's border policy has sparked outrage, but the Democrats need more to make an impact in November

Analysis: Amid all the other election issues - from immigration to taxes - President Trump is still at the centre of the battle over control for Congress in November's midterms

President Donald Trump has doubled down on his tough border policy (Leah Millis/Reuters)

Democrats may see the latest outrage over Donald Trump’s immigration policy and believe it is a chance to make headway ahead of the crucial Congressional elections in November – but things will not be so simple.

There is no doubt that Republicans are divided. Images of children being separated from their parents and placed in cages created by metal fencing at the US border will always be difficult to argue for. A number of Republicans – past and present – have spoken about the “cruel” nature of the “zero tolerance” policy over illegal crossings, and Democrats are keen to highlight the “inhumane” nature separating parents and children.

There are also the status of two immigration bills in Congress that are set to be discussed this week. Mr Trump’s muddled comments over the weekend that he would not sign a “moderate” bill, that were later walked back by the White House, did not help.

Beyond immigration, Mr Trump’s trade tariff spat with China, as well as Canada, the EU and Mexico, has made it difficult for Republicans in districts and seats whose residents will be directly affected by such moves, let alone the wider implications for the US economy.

In terms of voting in November, where the Democrats are looking to take back both the Senate and the House of Representatives, Democrats lead the generic ballot. Those numbers are based on polls asking which party voters would support in the midterm elections, with the Democrats holding an average lead of 47.3 per cent to Republicans 39.8 per cent. Although the latest polls do not possibly reflect the latest sentiments over what is happening on the border.

Democrats have pointed to the generic ballot as a reason for optimism about gathering momentum ahead of November. And it is true that they have been in the lead for more than a year. But the generic ballot is not always indicative of a final result, given the swings that can happen district to district.

There are other signs of positivity for Democrats, a wave of women candidates are making headway at the primaries to decide those going forward to the election in November. While many may have been inspired to run for office by the policies of Mr Trump, a number of candidates have sought to make clear that they are not just running an anti-Trump platform.

So far, Democrats have nominated women in just under 50 per cent of their open House primaries, 73 out of 150 races, according to the Cook Political Report. A move towards diversity will likely help Democrats in November.

Ian Russell, a former Democratic Congressional Campaign Committee deputy executive director told Politico that women are winning primaries at an “unprecedented” rate

“It’s not just opposition to Trump that is causing it,” he said. “That’s part of it, no question, but it’s also a sign that Democrats see the importance of women in our general election prospects.”

It is true that Democrats need to offer voters more than an anti-Trump message, as the president remains the Republicans most potent weapon. While his administration saying it “will not apologise” over the border policy will do little to halt the outpouring of criticism, Mr Trump has proven he can weather such storms.

In a recent Monmouth University poll, just 43 per cent of all adults surveyed approved of the job Mr Trump is doing, but a whopping 86 per cent of Republicans approved. While the result of the 12-14 June poll will do little to help moderate Republicans keep hold of toss-up seats, the GOP will likely need to make the most of the president’s numbers if it is to hold on to control of Congress.

As for the immigration debate, a 14-15 June Ipsos poll for The Daily Beast of 1,000 people – 27 per cent of the overall respondents agreed that it was “appropriate” to separate parents and children to deter others from crossing, while 56 per cent disagreed. Yet, Republicans leaned slightly more in favour, with 46 per cent agreeing with the statement and 32 percent disagreeing. Mr Trump doubling down on the policy plays to that base, and whether it is divisive or not, the GOP needs to keep hold of those voters.

This is because the Republican Party is increasingly becoming the Donald Trump party. Last week’s primaries showed a glimpse of that, with Mark Sanford, one of Trump’s most outspoken Republican critics in Congress, suffering the most striking defeat as Mr Trump backed his opponent. Mr Sanford is one of the last members of the class of 1994, where the Republicans had major success in the midterms.

Now, both parties have to contend with Mr Trump ahead of November. Republicans are tied to his agenda, while the Democrats have to make sure they offer a message that is not just anti-Trump.