Imposing a highly progressive tax income and estate tax structure to pay for the increased expenditures and to lessen the income and wealth gaps in the U. S.
If you look at actual tax revenues, the United States system is more progressive than other countries. Estate taxes in particular are already one of the highest tax rates in the US, and at 40% only five points behind the European leader (France). The top US rate is the fourth highest among OECD countries. The effective rate is 0% for poorer and most middle class people.
Similarly, the US gets 100% of its income tax revenues from about 50-55% of the people and 0% of its income tax revenues from the other 45-50%. Or the top 1% pay 45% of income taxes.
The CBO said that the average federal income tax rate paid by the top 1 percent has also dropped since 1979—falling from 22.7 percent in 1979 to 20.3 percent in 2011.
That's noteworthy because the 1979 tax rates are generally regarded as more progressive than the ones in 2011. The top rate has dropped from 70% in 1979 to 39.6% in 2011, but revenues increased. And in neither case did the effective tax rate come anywhere close to the nominal rate.
Progressive tax "rates" are not the main source of higher tax revenues. There may be reasons to do this, but tax revenues are not one of them.
Looking at other countries, the most successful method of increasing tax revenue has been to increase it on the middle class. While individually they have less money, there are more of them and they are less able to adjust to taxes via use of tax shelters. For example, Value-Added Taxes are almost universal in Europe.
All that said, political parties do not have to be realistic in their policy.
Democrats advocate increased tax rates, particularly on those with higher incomes.
Addressing social welfare and safety net needs by increasing federal non-defense governmental expenditures to 19% of GDP
The Democrats push for increasing social welfare and safety net spending. I don't know about a specific percentage of GDP. Republicans are mostly the status quo party on domestic spending, although some advocate decreases.
Keep combined state and local government expenditures steady at approximately 19% of GDP.
This is more consistent with the Democratic position, but they don't say it that way. At the state and local levels, they often advocate additional spending. But this is in part a reaction to the lack of spending by the federal government.
It's hard to have this kind of position on local spending in the US, as different politicians control spending at each of the five levels (federal, state, county, municipal, schools). The closest rhetoric is the argument that more federal spending would mean less of a need for more state and local spending.
Setting federal defense expenditures at approximately 5% of GDP ( a 10%+ increase)
Republicans push for increased defense spending. Note that 5% would be closer to a 50% increase than a 10% increase from 2016 levels. Democrats are mostly the status quo party on defense spending, although some advocate cuts.
Neither Democrats nor Republicans push for both those things at the same time. During the 1980s, this was actually the kind of deal that they made. More defense spending for Republicans and always increasing social spending for Democrats, combined with borrowing to replace tax revenues. But since the end of the Cold War, there has been less support for such deals.
As far as I know, none of the minor parties do either. Most third parties advocate a smaller military. This includes the Libertarians, the Greens, the Justice Party, and the Constitution party. The Greens advocate increased social spending and taxes, but the other two advocate decreased social spending and taxes. The Reform Party and the Modern Whig party support fiscal discipline, generally including less social spending. The Modern Whig party advocates for more defense spending.
As far as I can tell, there is no serious third party that wants to increase defense and social spending. Many want to increase one or the other. Some want to decrease both.