You can subset after getting the data for all states. See example below for the west coast along with HI and AK.
library(tidyverse)
library(tidycensus)
statelist <- c("AK", "HI", "CA", "WA", "OR")
estout <- get_acs(geography = "state",
variables="B01001_001",
year=2019,
survey="acs1",
geometry = TRUE,
shift_geo = TRUE)
#> Getting data from the 2019 1-year ACS
#> The one-year ACS provides data for geographies with populations of 65,000 and greater.
#> Using feature geometry obtained from the albersusa package
#> Please note: Alaska and Hawaii are being shifted and are not to scale.
fipslist <- fips_codes %>%
as_tibble() %>%
select(state, state_code) %>%
group_by(state, state_code) %>%
slice(1) %>%
ungroup() %>%
filter(state %in% statelist)
fipslist
#> # A tibble: 5 x 2
#> state state_code
#> <chr> <chr>
#> 1 AK 02
#> 2 CA 06
#> 3 HI 15
#> 4 OR 41
#> 5 WA 53
estsub <- estout %>%
filter(GEOID %in% c(fipslist$state_code))
estsub %>%
ggplot(aes(fill=estimate)) +
geom_sf()

Created on 2021-01-07 by the reprex package (v0.3.0)