What exact "border security issues" are holding up Ukraine and Israel aid packages in the US Congress?

Question

In the last few weeks, I've seen a number of articles about Ukraine aid being stalled by Congress Republicans.

BBC

Senate Republicans have blocked a move to pass an aid bill for Ukraine after failing to secure border compromises they sought in exchange.

The $110bn (£87.3bn) package included $61bn for Ukraine, as well as funds for Israel and aid for Gaza.

The White House has warned that US funds for Ukraine could soon run out.

A Ukrainian official said that failure to secure more US aid would mean a "very high possibility" that the war will be lost to Russia.

While Republican members are generally in favour of aid to Ukraine, some have sought to use the issue as a way to address mounting domestic concerns over the US southern border.

Reuters today is more specific but still rather vague.

WASHINGTON, Dec 10 (Reuters) - The White House will step up its engagement with U.S. lawmakers trying to strike a bipartisan deal that would provide military aid for Ukraine and Israel while tightening U.S. border security, a Democratic senator said on Sunday.

Republicans have insisted that additional funding for Ukraine must be paired with major U.S. border security changes but a bipartisan group of senators trying to broker a compromise have made little progress with less than a week before the U.S. Congress leaves for a Christmas break.

Reuters reported last week that the Biden administration was open to new limits on U.S. asylum as part of a deal to secure funding for allies Ukraine and Israel.

Murphy said the current border security demands by Republicans were "unreasonable" and that they were "playing games with the security of the world" by linking the military aid to U.S. border security measures.

Some Republicans have pushed for border provisions that would allow migrants crossing the border illegally to be quickly deported without the chance to seek U.S. asylum. They have also called for greatly scaling back Biden programs that have allowed hundreds of thousands of migrants to enter lawfully.

That's somewhat more informative than other articles, but it's still rather unspecific.

What are the Republicans holding out about?

• what policy changes do they want?

• are those policy changes likely compatible with US laws? Or, are they like Trump's initial "Muslim Ban" which was flawed from the start?

• if some of those policies have been the subject of polls by the public, how are popular/unpopular are they with the general public?

• which parts of Republican demands does the Biden administration most object to? They say they're open to compromise, so what do they consider not negotiable?

This seems like a very important topic in US politics, considering the consequences of no deal being reached. Most of the time both parties seem to craft immigration policies more to appeal to their respective bases (Reps being hysterical about it, Dems denying there's any problem) than to the center, so it's really hard to judge who is being reasonable and who is not without diving into the gory details. Which is why I am asking.

Answer 1

FWTW, this is a AP summary. It doesn't quote anyone in particular alas stating those Republican demands. TLDR version seems to be: more border wall, more border officers, more asylum applicants deported/removed and/or prevented from entering in the first place while their claim is processed/evaluated with them not being on US soil.

Changing the asylum system for migrants is a top priority for Republicans. They want to make it more difficult for asylum-seekers to prove in initial interviews that they have a credible fear of political, religious or racial persecution in their home country before advancing toward asylum in the United States.

Republicans in the House have passed legislation that would detain families at the border, require migrants to make the asylum claim at an official port of entry and either detain them or require them to remain outside the U.S. while their case is processed. [...]

Arizona Sen. Kyrsten Sinema, an independent who is part of the Senate negotiations, said in an Arizona radio interview that one of lawmakers’ goals is to ensure that “those who are here seeking asylum have an actual claim to asylum.”

[...] Negotiators have looked at steps that could be taken to reinforce existing infrastructure at the border, including hiring and boosting pay for border patrol officers and improving technology. One proposal advanced by a bipartisan group of senators would call for hiring of more border patrol agents, raising their pay and ensuring they receive overtime.

Biden has shown a willingness to accept tougher enforcement measures, recently resuming deportation of migrants to Venezuela and waiving federal laws to allow for the construction of border wall that began under then-President Donald Trump. The White House also wants to install new imaging technology at ports of entry that would allow authorities to quickly scan vehicles for illegal imports, including fentanyl.

Republicans say that is not enough. They want more robust improvements, including more expansive construction of a border wall.

Reuters however has a bit more details on the concrete Republican proposals:

Three prominent U.S. Senate Republicans on Monday proposed steps to restrict migrants from crossing into the U.S. from Mexico, including resuming construction of a border wall and keeping asylum seekers outside the U.S. while their case is heard.

The proposal emerged barely a week after House Speaker Mike Johnson, the top Republican in Congress, met with Senate party members and laid out his own plan to link Ukraine aid to Republican legislation known as "HR-2," which would restrict border access and set tight limits on asylum seekers.

No. 2 Senate Republican John Thune told reporters that Johnson's plan has "a lot" of support among Republicans in the Senate, adding: "It'd be strong."

The Republican-controlled House passed HR-2 in May, but the bill has gone nowhere in the Democratic-led Senate.

"These solutions, drawn from those found in HR-2, prioritize the concrete and significant policy reforms that are most critical to securing the border," said a one-page proposal released by Republican Senators Lindsey Graham, Tom Cotton and James Lankford.

Among other things, the Senate Republican proposal would resume construction of a border wall -- former President Donald Trump's signature goal -- in addition to deeming large numbers of migrants ineligible for asylum. It would also revive a controversial policy under which asylum seekers are told to remain in Mexico while their immigration case is heard.

So it seems the essence of their demands was laid out in that HR-2.