In 1996, the Republican party platform supported an amendment to end birthright citizenship:
"Illegal aliens should not receive public benefits other than emergency aid, and those who become parents while illegally in the United States should not be qualified to claim benefits for their offspring. Legal immigrants should depend for assistance on their sponsors, who are legally responsible for their financial well-being, not the American taxpayers. Just as we require "deadbeat dads" to provide for the children they bring into the world, we should require "deadbeat sponsors" to provide for the immigrants they bring into the country. We support a constitutional amendment or constitutionally-valid legislation declaring that children born in the United States of parents who are not legally present in the United States or who are not long-term residents are not automatically citizens."
https://www.presidency.ucsb.edu/documents/republican-party-platform-1996 Interestingly compared to the 2000 platform which had a lot of the same material, this amendment was not included. Bob Dole and Jack Kemp also both opposed it when asked by reporters. Some relevant tidbits in the party platform mention border security, Prop 187, making English the official language on a federal level, and a flag desecration amendment.
"Bill Clinton's immigration record does not match his rhetoric. While talking tough on illegal immigration, he has proposed a reduction in the number of border patrol agents authorized by the Republicans in Congress, has opposed the most successful border control program in decades (Operation Hold the Line in Texas), has opposed Proposition 187 in California which 60 percent of Californians supported, and has opposed Republican efforts to ensure that non-citizens do not take advantage of expensive welfare programs. Unlike Bill Clinton, we stand with the American people on immigration policy and will continue to reform and enforce our immigration laws to ensure that they reflect America's national interest."
"America's ethnic diversity within a shared national culture is one of our country's greatest strengths. While we benefit from our differences, we must also strengthen the ties that bind us to one another. Foremost among those is the flag. Its deliberate desecration is not "free speech," but an assault against our history and our hopes. We support a constitutional amendment that will restore to the people, through their elected representatives, their right to safeguard Old Glory. We condemn Bill Clinton's refusal, once again, to protect and preserve the most precious symbol of our Republic."
What contributed to this amendment getting on the party platform in 1996 but being removed in 2000? Also, have there been any similar proposals of note between 1996 and Trump stating he would end birthright citizenship by executive order in 2018?